Linux Color Calibration?

eweaver asks: "Windows has built-in color matching modules like ICM and sRBG, and 3rd-party solutions like Colorific and ColorBlind, but what is the Linux/XFree86 equivalent? Caldera Graphics seems to have some sort of solution, but I don't think it's universal, it seems to work only in their programs. What can I do so that the colors I see in all my Linux graphics apps (mainly GIMP and Blender) are accurate (adjusted for gamma, white point, lighting, etc.)?"

Comments

It's My Understanding..

[Fleet Admiral Ackbar]

that having a good monitor is 90% of the battle. LaCie's "blue" monitors are supposedly very good. A decent monitor shouldn't drift much. I use two SyncMaster 900IFTs, and they match very well, to these eyes at least.

Re:It's My Understanding..

[n8willis]

I use two SyncMaster 900IFTs, and they match very well, to these eyes at least.

Well, in the design world what's really important is that the monitor output matches the printed output; that's what color matching is all about.

Physical systems like Pantone were created so that, for spot colors anyway, we could all know that we were working with the same color because we referenced it with a number, and everyone who had a Pantone swatch book could look at an identical print. So we all have a common frame of reference. Of course, that only applies to spot colors and professional plate printing. With CMYK, even if your printer is Pantone calibrated, you still have to do the proofing stage to make sure the balance is right.

In the desktop-publishing/PC world, the final output is not done by a printing press with Pantone inks, it's done on a desktop inkjet. So specifying a Pantone color doesn't gain you anything, as printers vary wildly in there outputs. Hence the need for software (like Apple's ColorSync) that comes with a vast database of "color profiles" and can automatically map one device's capabilities to another (ie, your monitor -> your printer for prrofs, and then your monitor -> The Big Printer for production usage). It's not providing a common frame of reference, but relative mappings.

I hadn't heard of that Caldera Graphics product; it sounds interesting, but as it appears to have been written by ESL, I'm not sure I'm getting all the details accurately. Any Francophones out there?

Nate

Re:It's My Understanding..

[MikeBabcock]

I hadn't heard of that Caldera Graphics product; it sounds interesting, but as it appears to have been written by ESL, I'm not sure I'm getting all the details accurately. Any Francophones out there?

Yup ... what did you need translated?

Re:It's My Understanding..

[eweaver]

Incidentally, I (the question poster) have a very new Samsung SyncMaster 950p, which is very nice. They trouble is, when I do Blender work under Linux, I really can't tell what it's going to look like in color-calibrated Windows. And Blender in Windows is significantly slower. My Epson Stylus Color 600 almost matches my Windows monitor display now, it's just a bit warmer. But Linux is nothing like it at all.

Re:It's My Understanding..

[jmccay]

I don't knw how closely you could match the colors exactly from one monitor to another. You could get close, but it may not be possible to show some colors on some monitors.
It all depends on what the monitor is using to generate the colors (the actual phosphur(sp?)). If you know the coordinates of the phosphurs, you could plot them on a 2d map of the visible light spectrum. The coordinates would define all the possible colors you could display with that monitor.
I believe the same could be done with the colors used in printing, but i am not sure. You may run into problems with the borders colors of the printer and monitor. In other words you coudl end up with colors that can't be generated on the printer but can be generated on the monitor, and you could also end up with colors that are not on the monitor but exist on the printer.
If you were to have a program to do matching you'd want to test the border colors of a given triangle. You'd want to test the border colors for both a printer and a monitor. I would think these would be printer/monitor specific.

Emulation

[buttfucker2000]

Try:
vmware
Plex86
Basilisk

Basically anything that gets you out of X, which is exceptionally primitive, lacking as it does alpha blending, true type fonts, etc., and being useful only for people running software over a network.

I'm not trying to be rude, but if you're going to do graphic design work, you should use a graphics design tool - in other words not X, which is unsuitable - how could you present as work those ugly blocky fonts?

If you want to do anything I recommend a good set of tools - if you're doing cross-country driving I'd recommend a 4 by 4 vehicle - to use a cadillac would be silly, and if you're going to do graphic design work you should use a graphic designer's tool - a Macintosh or Windows.

Re:Emulation

[einhverfr]

You might do well to consider some things before you write:
("If you want to do anything I recommend a good set of tools - if you're doing cross-country driving I'd recommend a 4 by 4 vehicle - to use a cadillac would be silly, and if you're going to do graphic design work you should use a graphic designer's tool - a Macintosh or Windows.")

1: XFree86 4.0 does support true type fonts.

2: A windowing system hardly qualifies as a graphic designer's tool. I prefer to use the GIMP, Photoshop, etc. for such work.

As far as color calibration goes, I am not aware of any technologies either in existance or under development. Such technology should be doable AND, if I remember right, teh XF86Config file allows a path for the color files. THese should be calibratable, but I am not entirely sure how to do this at this time. Furthermore, this feature should allow you you export your custom palatte and share it with a friend.

Re:Emulation

[Stephen Samuel]

Even if Linux doesn't currently have good color calibration software, that doesn't mean that it's not going to. Some people may think that a Mac is the best venue for doing publication work, but SGIs have also been used for quite a while for the same purpose. We can always hope for yet more technology transfer from the SGI world into the Linux world (probably easier than a transfer from the Wintendo/Mac world).

As for the question of "why calibrate": it's mostly for publication purposes. When you're doing up an Add that's going to get 1 Million Dead Tree copies, it's worth spending the time and money to make sure that the soft blue hue isn't going to come out light navy (worst case).

For stuff that's going to get 1 million Dead Electron (Video) impressions, there's no way to make sure that the color on your screen is going to be seen exactly the same on another screen. On the other hand, if you have a (reasonably) well calibrated screen, there's at least some hope that things won't be as far out on average.

Example: If you're calibrated good, and I'm dark, your work will seem no worse than most other good images. On the other hand: If you're calibrated light and I'm calibrated dark, your image may still stand out as noticibly bad on my (already improperly calibrated) video screen.

If you're the only person who's going to see your graphics work, then calibration isn't terribly necessary. On the other hand, simple calibration will make it easier to match stuff from your scanner and it's usually nice to know that you're seeing an image in somewhat the same colors as was intended by the artist that created it.
`ø,,ø`ø,,ø!

Re:Emulation

[loren]

First, color-correction has very little to do with alpha channeling, or anti-aliased fonts. Some things like gamma correction and black-value adjustment should be very easy to add to X... although they may require an extra back-buffer in the X server. The "real" color correction technologies that are found in commercial OSes aren't going to be found in (at least free) X servers, unfortunately, because this technology is very heavily patent-protected. This is part of why professional packages like Adobe Photoshop are so expensive.

As far as alpha-channeling and anti-aliasing (both fonts and primitives), you are correct in indicating that (with current protocols) these are impossible for X to support natively. (Maybe in X11R7, or in X12.) Many programs have worked around these limitations, however, by rendering primitives and fonts independantly of X's basic drawing capibilities. If I am not mistaken, the newest versions of GTK (a very commonly used GUI tool-kit in open-sourced applications) will render fonts this way using freetype, as an option, if not the default.

Re:Emulation

[GypC]

You really like to talk about things of which you know nothing, don't you?

Try using the Gimp to create a banner... use some True-Type fonts (which, by the way, work fine with older versions of X as long as you have a font server that supports them, like xfstt). OK, use the text tool, type in your message, press OK.

Oh look! Those letters in the image are antialiased! Gee, what a suprise, and here I was thinking that buttfucker2000 knew his ass from a hole in the ground.

Look, dipshit (and I wouldn't be so rude if you weren't obviously either a liar or a parrot), X can't antialias fonts that it draws directly (because the X protocol treats fonts as a 1-bit mask), but any application can take the task unto itself and antialias whatever the hell it wants to.

"Free your mind and your ass will follow"

Re:Emulation

[Tet]

For stuff that's going to get 1 million Dead Electron (Video) impressions, there's no way to make sure that the color on your screen is going to be seen exactly the same on another screen.

Of course there is. That's why graphic formats like TIFF (and nowadays, PNG) let you include a colour profile, precisely so that the image does look the same on all screens. Of course, if the target monitor isn't calibrated in the first place, then no amount of colour profiling will help, but the intentions are good... With the world apparently moving towards sRGB, hopefully this will become less of an issue in the future.

Re:Emulation

[drinkypoo]

If you want to do anything I recommend a good set of tools - if you're doing cross-country driving I'd recommend a 4 by 4 vehicle - to use a cadillac would be silly, and if you're going to do graphic design work you should use a graphic designer's tool - a Macintosh or Windows.

This illustrates my next point perfectly. You believe that a 4x4 is the best vehicle for cross-country driving. Those of us who pay attention to such things know that the Cadillac gets better mileage and is more comfortable when you're driving for hours.

But that's all a matter of opinion, maybe your ass has a different shape than mine and the four-by works out better. Similarly, you may think the best platform is MacOS or Windoze (I actually would use windows myself) but someone else may want to use linux.

Instead of wasting bandwidth telling people to use a different OS, why don't you just bugger off if you don't have something useful to contribute? It's clear you only wanted to start some shit and be argumentative. He'll use linux, you'll use something else, and everything will be fine.

Re:Emulation

[ianezz]

• lacking alpha blending: alpha blending (and font antialiasing) can be easily done by the user apps that require it - having the support directly in the X server is nice and desiderable (XFree86 4.x implements such extensions, so toolkits like Qt or GTK+ can start using them and providing nice API), but absolutely not required (The Gimp does alpha blending and antialiasing by itself, the same is true for Gnome Canvas and Swing of Java memories).
• true type fonts: come on, please! There has been True Type font support for ages through appropriate X font servers. And you can easily have them along with Compugraphic fonts and the usual Adobe Type 1 (and more esotic sorts) by simply using an X font server. And graphic applications can smooth them by themselves (i.e. The Gimp, apps using the Gnome Canvas widget, GhostScript when rendering PostScript text, or Acrobat Reader - they all use antialiased fonts and graphics where they are required).
• how could you present as work those ugly blochaveky fonts?: come on, please (again)! You can have all the vectorial fonts you want (even a hight-quality edition of the 35 standard PostScript fonts, search on Goole for URW fonts, but if you have GhostScript you probably have them already), and graphics programs can do antialiasing by themselves.

That said: X is not the best at everything, and color calibration is one of these. If there is enough interest, it will be implemented as an extension to the X protocol. Instead of bashing X, go after X implementors, like the XFree86 group, and ask or help them to properly design and implement such thing. Then you'll have fine color calibration in X.

Re:Emulation

[drinkypoo]

try "cross-country" without the american bias - it's more like what you'd consider "cross-country running." it's off-road. the comment makes sense.

Then yes, your comment makes more sense. I am however rarely concerned about avoiding an american bias except when writing.

Furthermore, please explain exactly what parts of my post you disagree with, outside of the metaphorical, or stop posting to slashdot. You add unnecessary load.

Re:Emulation

[Nailer]

Your a troll. I'm biting.

*
Alpha blending is being worked on by Keith Packard of SuSE inc. and the brilliant XFree86 team, and should be implemented in a future version of XFree86

* True type fonts have been around for over 2 years and are standard on all major distros. XFree 3 uses an external font server like xfstt, XFree 4 handles them natively.

* etc? True, X lacks color correction. But XFree 4s modular interface allows for a companys to sell closed source X modules AFAIK, so an Apple ColorSync module should be possible. Why not do something constructive and mail them about it?

Re:Emulation

[nathanh]

Basically anything that gets you out of X, which is exceptionally primitive,

Oh really, let's see why you think this...

lacking as it does alpha blending,

Xrender does this, and it is an X11 extension.

true type fonts,

XFree86 4.0 supports TrueType and Type-1 fonts.

etc., and being useful only for people running software over a network.

All shared resource systems need some form of IPC between the clients (many) and the resource (single). In Windows this is message passing. In XFree86 it is named pipes. Named pipes are more primitive (and faster) than message passing. X11 is not slow. This is a MYTH.

The problem is that people confuse windowing systems (many clients, 1 framebuffer) with games and other direct rendering problems (1 client, 1 framebuffer). They conclude that any windowing system which can't perform as quickly as a plain framebuffer is "broken", "stupid" or "only good for networked graphics". This is plain wrong.

For direct rendering, which is where you have a single client and a single resource, then the highest speed is achieved by locking the resource and performing Direct Rendering. You might have noticed that Windows only recently offered direct rendering as a feature: years after SGI offered direct rendering for OpenGL over X11. XFree86 now offers two forms of direct rendering: DGA or DRI.

We have the fastest possible IPC for indirect rendering (named pipes) and the fastest possible methods for direct rendering. So why is there a still pervasive myth that X11 is broken? Display Postscript, Direct Rendering, OpenGL, Type-1 and TrueType fonts... WHAT MORE DO YOU WANT?

Sure, X11 isn't perfect, but this is because it's a non-trivial system and it certainly seems people prefer to whine about it rather than help out in development.

If you prefer to do things, rather than talk about it, then go to www.xfree86.org and join up for development. There are many things that need to be done and far too few people working on it.

Re:Emulation

[piggy]

For what it's worth, NeXTstep did not use X-Windows (or even an X-Windows based system) as its windowing system. It used Display Postscript, a version of Postscript aimed at digital displays rather than printers. The idea was that you would be using the same Postscript image description for display as you would be for printing.

On a side note, Mac OS X (descended from NeXTstep) uses Quartz, which is sort of a Display PDF, for similar reasons.

X could be extended, but that doesn't help the question asker now.

Russell Ahrens

Re:Leave color calibration to desktop publishers.

[Kamelion]

Color calibration is important if you are doing any type of graphic you want others to be able to work with on their machine. I've had no end of problems with POVRAY and SDL for Dalek Chess. When I think I have something that will look good for everyone I come to work and find that half of the PC's that pull up my web page either are too dim to see the detail or washed out. It even varies from Linux box to Linux box.

No answers here, but I would love to see a solution.

Correction

[buttfucker2000]

> being useful only for people running software over a network.

change that to 'being most suitable for' - as explained, you can use an inappropriate tool, but it's not the best way to do things.

Re:Leave color calibration to desktop publishers.

[h_jurvanen]

Seriously, why do you need to calibrate your color?

It's probably a desktop publisher that's asking the question! If Linux advocates want it to be accepted past its current geeky bounds, it is going to have to start incorporating features used by people from other walks of life.

Herbie J.

Color calibration

[Mickey Squid]

I manage a prepress department where color issues and color calibration are very important. The Mac and to a lesser extent Window have color calibration built into the OS. I don't know of any ICC profiling or calibration for Linux, but I haven't used Gimp in a while either so I don't remember. In any case an ICC profile or other file for monitor calibration is only the first step and lacking built in profiling you can alway purchase a monitor which has this ability built in. Some on the Mistubishi monitors for example. Understand that any time you change the lighting in your room recalibration will be required in order to maintain absolute color accuracy. You probably don't really need this accuracy and I recommend that you get a monity wich gamma correction built in, create a graphic with lots of colors in it (the more diversity of color the better), take that graphic on disk (or ftp) to a graphics service bureau and have them output a digital on their color corrected equipment. Put your room in the most commonly used lighting setup, hold your digital next to your monitor and adjust the gamma correction settings on you monitor until you get pretty good match. It is better to go a little dark that a little light. Paritcilary watch the reds and the blues. Also remeber that Gimp uses the RGB color space exclusively and the digital is output on a CMYK printer which has a smaller color space (is capable of fewer colors). When you get a good match between your digital and your monitor you are 95-97% as accurate as the big boys with thousands of dollars worth of color calibration equipment.

Re:Color calibration

[cfish]

The problem with this approach is that you colibre your monitor relative to your printer. i.e. trusting that your printer is correct.

While nearly nothing is absolutely correct, and not many people need them to be correct anyway, I think the stone age method still apply - get a little booklet of Pantone colors and compare it directly with the computer.

As a programmer and a graphics designer, I must say, I have my linux box contrast adjusted to really low because i need the text to be crisp. Programmers need crispness 100 times more than correct colors.

Re:Color calibration

[ebh]

This is a great illustration of just how much of a Black Art color calibration really is.

Another example. I bought an Epson Stylus Photo printer to go with my digicam. I did everything one normally does to calibrate my monitor, including putting finer control over room lighting. I then do everything the FAQs say to do to get color spaces consistent in (Windoze) Photoshop and in the printer driver. I bring the digicam photos into Photoshop, get everything looking right, and presto, my son turns green when I print him out, even though I know he didn't eat anything funny or spin around too many times before the photo was taken.

It's enough to make me go buy a Mac, just for this one application.

(Sidebar: good luck getting Pantone to go open source!)

Re:Color calibration

[ocelotbob]

Dunno if this is what you're talking 'bout, but you can create color adjustment profiles where you can tweak the amounts of colors, brightness, gamma, and contrast you send out to a printer in the latest betas of the GIMP (since 1.21, IIRC). Don't know how accurate the results truly are, as most of the stuff I do doesn't have a need to be truly color accurate.

Re:Color calibration

[rtaylor]

> take that graphic on disk (or ftp) to a
> graphics service bureau and have them output a
> digital on their color corrected equipment.

Might want to read that one again... He mentioned you had to print it out on colour corrected equipment.

Re:Color calibration

[greenfield]

Minor nit: CMYK is not capable of fewer colors than RGB; the CMYK and RGB color spaces are not subsets of each other, although they do intersect.

Re:Color calibration

[ideut]

the CMYK and RGB color spaces are not subsets of each other

Of course, if they were subsets of each other, they would be equal to each other, ideut.

Re:Color calibration

[greenfield]

*sigh*

CMYK is not a subset of RGB _and_ RGB is not a subset of CMYK.

Re:Color Calibration

[dead_penguin]

Unfortunately most X servers don't do anything with these options. They're there for compatibility with those servers that *do*, but passing a gamma value (single channel or overall) to X usually results in nothing new happening. I haven't had a chance to play with Xfree 4 yet, but I'd be surprised if too much has changed there. It doesn't seem to be on the priority list of too many people.

Re:Color calibration

[ideut]

Thank you sir. I particularly enjoyed the sighing part. What I still don't understand is, *what* is RGB if it is not a subset of CMYK?

Re:Color calibration

[waynem77]

What I still don't understand is, *what* is RGB if it is not a subset of CMYK?

• RGB is a color model based on the interaction of light. It is well-suited to, say, computer monitors.
• CYMK is a color model based on the interaction of inks. It is well-suited to, say, prints.
• The color spaces of the two models are such that neither one is a subset of the other. In other words, it is possible to describe a color in RGB that is impossible to describe in CYMK, and vice versa.

• Helpful? Yes? No?

Re:Color calibration

[esonik]

The gamut of RGB and CMYK intersect, but none of both is a strict subsect of the other, see
here (at bottom of the page).

They say:
"Both models [RGB and CYMK] fall short of reproducing all the colors we can see. Furthermore, they differ to such an extent that there are many RGB colors that cannot be produced using CMY(K), and similarly, there are some CMY colors that cannot be produced using RGB."

Re:Color calibration

[ideut]

Yes. What color sensors do we have in our eyes?

Re:It's not a major priority now

[rigau]

There are no professional graphic designers or publisher that use Linux.

There are no REAL professional graphic designers or publisher that use Windows either.
They use macs because of ColorSync and because Photoshop actually runs much much better on macs.

Color Calibration

[Luguber123]

The only thing you need to calibrate these colors (using software that is), is the image you would use to calibrate gamma and such in various games, you can find some of these in the Mesa-project (www.mesa3d.org). Personally I've no use in calibrating my colors, but designers that work in teams should be calibrated very closely to some standard so that not all the clients will have to adjust their monitor for just this app/game/website or whatever they make. If your monitor doesn't have an adjustment for each color, you can tell the X-server to use a offset for each channel. This can be a little bit tricky especially if you are using a display manager. But if you are using startx, just make sure that startx (which is a shellscript) calls X with the required parameters. Do this to find what you are looking for $ X --help

XRainbow

[ElfMagic]

I recall kate fenton (katedown@hotmail.com) from SGI coming up with an app called xrainbow last summer that did exactly this, however I cannot find the url to the project's homepage. You might try contacting her about it..I contributed a bit of source to this, but I cannot for the life of me find the source nor binary..I'll continue to look and post a url to the source when I find it..it's gotta be on one of 300 or so cd-rs laying around here :)

Re:XRainbow

[Zurk]

http://www.google.com/search?q=cache:archiv.leo.or g/pub/comp/usenet/comp.sources.x/xrainbo w/+xrainbow&hl=en&lr=lang_en

yup. it works.

Re:Leave color calibration to desktop publishers.

[AFCArchvile]

If Linux advocates want it to be accepted past its current geeky bounds, it is going to have to start incorporating features used by people from other walks of life.

Okay, but once a fully-functional AOL client for Linux is made, then the entire Linux effort will have to be killed like a wounded horse.

color swatches

[danboy]

I have generally found calibrating my monitor to be a waste of time since in order for it to be trully effective everyone's monitor must be calibrated the same. Instead I really on color swatches such as the ones you can get from pantone. they give you a real world representation of a color so you know what it will look like in print, and they usually hold up pretty well across monitors.

Get a Mac.

[Pope Slackman]

Seriously.
AFAIK, X(At least the free variant) has no support for color balance, calibration, matching or, well, anything.
(X might do gamma, but that's it.)

Linux is a great OS, but it can't do *everything*.
There are some areas where Macs and even Windoze beat the hell out of it.
One of those areas is graphics.

BTW, OSX beta /rocks/. Check it out if you get a chance.

--K
---

Re:Get a Mac.

[Stephen Samuel]

From X --help:

-cc int default color visual class
-co file color database file
...
-gamma f set gamma value (0.1 < f < 10.0) Default: 1.0
-rgamma f set gamma value for red phase
-ggamma f set gamma value for green phase
-bgamma f set gamma value for blue phase

I don't use them personally, but I'm sure that people can come up with tools that would make using these (and other X color support features) easy for non-geek pre-production types.
`ø,,ø`ø,,ø!

XF86 will have to ditch XF86Config first.

[AFCArchvile]

Seriously, that could be retooled into one standardized control panel. In other OSes, it is not necessary to enter in the horizontal refresh rate if you already know the vertical refresh rate; the horizontal refresh rate can be calculated if you know the vertical.

Also, it would be nice to be able to adjust the resolution of X while actually in X. When you tweak with the XF86Config in vim and then try to start X, only to have it terminate because it doen't like one line, it just becomes so exasperating.

In short, Windows has a GUI display control panel, MacOS has a GUI display control panel, so why doesn't Linux have one yet? They've only had about five years to make one, so there's no excuse.

Re:XF86 will have to ditch XF86Config first.

[gibson_81]

Also, it would be nice to be able to adjust the resolution of X while actually in X.

Hint: /usr/X11R6/bin/xvidtune.

They've only had about five years to make one, so there's no excuse.

Oh yeah. I mean, it's not like there are any differences between Linux today and Linux 5 years ago ... of course they've just been sitting around on their lazy asses doing nothing ...

Re:XF86 will have to ditch XF86Config first.

[iomud]

ctrl+alt + or - will change the res in x. go figure learn something new every day!

Re:XF86 will have to ditch XF86Config first.

[GrenDel Fuego]

That only works if you have multiple resolutions defined.

I personally only define the one resolution that I generally use due to X automatically changing the virtual desktop space to the higest of the defined resolutions.

If I want to change my resolution, I think that the desktop area should be changed right along with it. I know not everyone would want this, but it should at least be an option!

Re:XF86 will have to ditch XF86Config first.

[BZ]

As a matter of fact, XFree 4.0.1 will autodetect any reasonably modern monitor's VESA modes and use them. There are no longer any modelines in the XF86Config file unless you feel a pressing need to put them there.

Re:XF86 will have to ditch XF86Config first.

[dead_penguin]

That only changes monitor resolution. If you start with a 1024x768 desktop and zoom in with this, you still have a 1024x768 desktop. It's kind of handy if you want to zoom in on an image or something, but absolutely useless (IMO) if you are trying to do work. This method is little more than a neat hack added to X. For resolution changing to be useful in X, the desktop would need to be automagically resized to match the screen resolution. I don't see this being possible without major changes to the X infrastructure-- or without having to restart X and all apps currently running (a move that's almost windowish). Maybe this is another indication that X is flawed and we should ditch it completely in favour of something new...

Re:XF86 will have to ditch XF86Config first.

[Abreu]

Mandrake has a (beta?) utility called DrakX that does what you describe...

I use the one on Mandrake 7.0, which is still pretty beta, but I assume that the one included in 7.2 will be better (gotta get me an upgrade from cheapbytes...)

Re:XF86 will have to ditch XF86Config first.

[quist]

the horizontal refresh rate can be calculated if you know the vertical

It's not that cut and dried. A vertical rate will yield a range of valid horizontal rates for a given dot clock frequency.

X isn't restricted to the off-the-rack common screen resolutions--you can run all kinds of oddball combinations in an effort to squeeze performance out of your gear. Try running 944x708 from the Windows control panel! See the the XFree Video Timings HOWTO for details.

-q

Re:XF86 will have to ditch XF86Config first.

[Oninoshiko]

ok i have an ABSOLUTLY awsome HP workstation monitor that i picked up for 5$ a piece. (ok i have 2 (dual heads good, napster bad)) perfictly sharp images because you have the dials on the front to manualy tune the guns. the only problem is that it is a a fixed freq monitor.in comparison ATM im in a lab and im getting a headache from the misaligned guns. that means being able to use the monitor lines like that becomes an ADVANTAGE (the horozontal refesh rate is really the key to fixed freq displays). it took me all day to get the line right, but they dont eve work under windows at all.

Oninoshiko

Font smoothing

[buttfucker2000]

Sorry. I meant font smoothing where I wrote true type fonts - hence the blocky fonts - basically anything above 14pt is not of production quality unless you've got font smoothing (anti-aliasing).

Re:Font smoothing

[Dr. Evil]

In one of your other posts, you mentioned banner ads without font smoothing/antialiasing. The GIMP does antialiasing. As for colour matching, I never had a need for it, but I never did professional publishing. When I need colour accuracy, I paint by numbers.

I see the lack of Truetype as a greater impedement to amateur desktop publishing. Truetype is excellent for people who care about what their work looks like while they're making it, but it is not as good as other font formats for the final output (Think small caps, character kerning etc.). And Linux, unlike Windows 3.1 doesn't support Truetype, it supports hacking truetype into an X-like font, or rendering truetype on the screen, but linux, unlike Windows 3.1 has no underlying printing architecture.

Read up on why Abiword uses Truetype under Windows, but not under Linux for more information:

http://www.abisource.com/faquser.phtml #2. 7

Besides, with no printing architecture (which I believe Gnome is working on correcting), you certainly couldn't do ICC on printers anyways.

http://developer.gnome.org /ar ch/imaging/printing.html -- I hope somebody's touched that since its September 1998 date.

That about exhausts my knowledge of printing, fonts and graphics. Some day I'll have to get my hands dirty on these projects.

Re:Font smoothing

[Dr. Evil]

Not quite true. Most applications use the printer driver to optimize the output. While it is confusing and it rather sucks, it makes more sense to have the printer say "I have an internal font which represents this TrueType font as though it were a postscript font."

It also makes a difference for various resolutions. 150dpi will print characters better with particular properties than than will 180, 300, 360, or 600 dpi.

Tack on other limitations such as the printable area and it makes sense that the document will reformat itself for the printer.

If you take several reasonably well written printer drivers for printers genuinely capable of printing the same resolution ( 300dpi doesn't mean each pixel is 1/300th of an inch. ), and you disable font substitution and other similar printer based enhancements... or if you simply run the printers in compatability mode (using the same drivers), then you will not have this "problem."

If you want the same thing output every time regardless of the person's machine (scaled down depending on the printable area) use a PDF. You can also use a generic postscript driver and Ghostscript... the same way that Linux prints.

Some info

[raph]

A fair amount of info on color management tools is on my color management page. One of the most exciting pieces of technology is the Argyll color management system.

The main thing that's lacking right now is integration. A lot of the pieces exist, but they're tied together yet. I plan on integrating Argyll into Ghostscript over the next few months, so that's likely to be a good start.

Interestingly enough, X had a very good start at a color management system (XCMS). However, as far as I know, nobody ever used this seriously, so it's yet another hunk of worthless junk hanging off the X server. This type of thing still "works", though:

xterm -fg CIEXYZ:0.371298/0.201443/0.059418

Of course, the chance of your monitor actually matching the CIE color is pretty close to nil.

In any case, there's quite a bit of work underway, and it's reasonable to expect that Linux will eventually have good color management. If you want it sooner rather than later, contribute to one of the projects!

man -k Color Conversion Contexts

[Wills]

Have you read the man pages on using XcmsCCC structs to define a color calibration in X?

man XcmsSetWhitePoint

man XcmsCreateCCC

BTW, has "DLL hell" got to Linux? I mean there're all those nasty incompatibilities between different versions of the libc shared libraries, like libc5, glibc-2.0, glibc-2.1, etc.

What's the best way to organise /lib /usr/lib /etc/ld.so.conf so you can have all of the glibc versions and dynamically linked programs available?

Color calibration- why bother?

[solios]

There's really not much point to it in linux, and there probably won't be a demand for it for quite some time. Seriously- how many Linux / UNIX users use their systems for graphics? (I would be interested to see what IRIX has in the way of calibration utilities).

If you're looking to do serious graphics work and monitor calibration is a MUST, forget linux and Windows. Macintosh has lasted this long because of colorsync and the fact that Photoshop seems to run a hell of a lot smoother on a RISC processor. If Adobe, Macromedia and Quark ceased support for the Mac, Apple would be a ghost within a year.

The Mac was DESIGNED for content creation, with a huge emphasis on making the UI a tool for the artist instead of an obstacle.

Windows has become more of an entertainment medium, and IRIX handles the super-high-end 3d on the SGI systems.

Linux does everything else quite nicely, but as a SERIOUS graphics tool, it's a joke. Until either X gets a boost or a better open-source / free windowing system comes along, accept the fact that Linux simply can NOT fill EVERY need for EVERY person who uses a computer in the course of a days work.

Re:Color calibration- why bother?

[MadCow42]

Actually, there are some very HIGH-END graphics systems based on UNIX... the company I work for sells a system called "Repri" as a photographic retouching station. Repri is known in the social imaging industry as "the" premier retouching system, and the Repri Color Space is ideal for representing photographic color on a computer monitor.

Now, having said that, this color management system is not available independently from the Repri system, but it shows that it can, and has been done very well on the UNIX platform.

(FYI, it runs on an SGI O2 box)

Check out the Sienna Imaging Home Page for info.

Gnome

[realkiwi]

Programs/Settings/Imlib Configuration Options

My screen is set to match the gamma of the Macs in the office. That way things don't go bad when exchanging pics between the two OS.

After that we look at them in Windoze to see if they are too dark.

Et Voila

Who said "real" graphics people don't use Linux!!!

Gimp rocks!!!

Deal with windows now..

[nirvana_am_i]

I love linux, but it cant do what i like to do and that is play around with graphics software like.. 3dsmax, Fireworks, Flash, Director, Freehand, Illustrator, Photoshop, Pagemaker, etc.. The list keeps going on and on.

The best thing for you to do in my opinion is to just use Windows 9x/2k or MacOS9/X and not waste anytime.. I tried out X for graphics, but it just doesnt cut it .. yet.

Linux is gaining ground in the backend and server platform industry, and has a ways to go even before it becomes a mainstream workstation platform before it becomes a graphics workstation standard like Macs or SGI.

If you want to do it cheaply and without too much hassle, stick with what you had before you started playing around with Linux.

Thats enough bs from me.

Everything has to negotiate

[Anonymous Coward]

The main advantage of color calibration is not just so that your monitor can agree on a color with whatever piece of paper or other display you're comparing it to (exactitude is impossible for a number of reasons). The main advantage is that your various devices can agree with each other; so that the color shift on your monitor is compensated for RELATIVE to your cheesy ink-jet printer as well as the printshop across town that's managing the color seperations. (and, likewise, the files created by your various graphics programs agree on color values relative to each other; color management is much more surreal than it seems like it should be)

Apple's ColorSync absolutely rules at this because it's platform-wide and any user can build a new color profile. Frankly, if the various X graphic apps could do color management right, Linux/Unix could become a serious graphics platform. Well, that and font/bezier antialiasing. And featureset parity. And so on. But it'd be one of the major hurdles to overcome, even if it's one of the least sexy.

Most hackers think of 3D when they think of graphics, but the vast majority of the graphic design community's bread and butter is 2-D work; page layouts, photo work, and so on. I could make a small 3D animated movie on my Linux-only laptop, but i couldn't make a business card for a client.

color management... Yee Ha!

[capsteve]

macs have it and pc's have it. even server applications such as xinet's fullpress(appletalk file sharing and opi solution) has a method for applying icc profiles to images stored in specified directories. why shouldn't linux apps have this? color management will make the linux server/workstation more useful in prepress applications, rendering engines(postscript/ghostscript/pdf rips), even shopping carts. mantaining a closer relationship to color management developments and keeping in line with other platforms is an advantage, not neccesarily a waste...

There is an old saying. . .

[kfg]

Used by athletes, martial artists, and even musicians.

Rely on your strengths, WORK on you weaknesses.

Linux is not *a* tool, but rather a collection of tools. It's silly to say the toolkit shouldn't be expanded and refined.

What's more, it is in the very nature of Linux to at least attempt to be a jack of all trades, since it is made up by the users themselves.

Graphics capabilities are the major weakness of Linux in the field of modern OSes. This is not inate to Linux, it is a FLAW that can be fixed without any degradation of any of its other useful functions.

What is Linux REALLY good at? Anything we as a group can code for it. THAT is the whole point of Linux and its only real strength.

Re:There is an old saying. . .

[gimp999]

What is Linux REALLY good at? Anything we as a group can code for it. THAT is the whole point of Linux and its only real strength.

And its weakness of course. How many graphic designers do you know who have the ability to contribute to open-source graphics application projects? Why do you think virtually all useful open-source projects are by developers for developers? This is not a bad thing.

Re:There is an old saying. . .

[kfg]

But of course. It is the primary weakness that the "industry" keeps harping on. Every strength has its concurent weakness.

As for your question, at least enough to have produced The Gimp, but they wrote it for X.

It's time to draw a big X on X and drive a wooden stake into its crippled little heart.

Re:There is an old saying. . .

[aengblom]

I dunno, how many open-source developers can design useful open-source Graphic User Interfaces. Why do you think virtually all useful open-source projects have weak graphic interfaces? Similarly, why should any graphics guru help linux... if it doesn't...and it's users/creators don't want it to...be a system that the graphics people can use.

OK OK. A bit of a troll, but you get my point. Graphics people could certainly use a quality, stable, OS that used its hardware efficiently. Graphics people don't want to need a pricey machine to make their work possible. Yes, it sucks when your server crashes, but it also sucks when that image you've been tweaking for 45 minutes goes down the tube. -d (sorry shift button broken.. all caps done by repeated caps-lock hitting...which got old :) )

Re: Get a Mac : why not ?

[pruneau]

...Then the poor guy will complain that linux on Mac does not support color calibration...

Why in the hell linux should not be supporting stuff that those hard-core linux bigots are looking their nose down to ?

I'm sure that in a few years, the same bigots will brag around the fact that linux IS the OS of choice for desktops : and that will be because color calibration and other so-called "useless" features are going to be available.

The real reason why MacOS and Win* are more appealing to graphists are marketing ones. They did every effort to please their customers, including aestethic ones : why not linux ?
I'm sure that having a free/stable/etc OS is something appealing to them too ?

On the other hand, why could not those graphic-oriented guys teach something to us ? Because you know root password and how to hack the kernel does not means you have nothing to learn from those guys ?

It's like we are back into the middle-age revival, when people at least realized that beautifull != useless.

/Pissed of.

Re:It's not a major priority now

[garcia]

I have not used Photoshop on a G4, but I have used it on PowerPC's and G3's. It is NOT faster than my k6-2 350 or my 500+ (OC'd to fit in the 133mhz bus). In fact, it crashes a lot and it is rather annoying.

that is just my observation...

Re:It's not a major priority now

[homoted]

Actually they are, there have allways been people that used Adobe Pagemaker on the Windows platform instead of Quark on a Mac.

Ok, so PageMaker really sucks on Windows, probably on Mac too :-). It's because of this that Adobe rewrote PageMaker from scratch, they call it "InDesign" now which is more of a competion to Quark, mostly because it is actually usable compared to PageMaker.

You see alot of people swithcing from Quark to Indesign because it's hasn't such a hefty price tag, and because you basically can do the same stuff in it as Quark.

Re:Leave color calibration to desktop publishers.

[pivo]

Your ignorance is showing. I'm a linux geek, I've been using the OS since 1.2.x, but I'm also an advanced amature photographer who knows the value of color calibration. Likening color calibration to AOL is like saying Linux shouldn't be a good good graphics platform because then it'll be too useful.

No excuse - it's open source!

[Midnight Ryder]

In short, Windows has a GUI display control panel, MacOS has a GUI display control panel, so why doesn't Linux have one yet? They've only had about five years to make one, so there's no excuse.

Ya know, you are right - there is no excuse for the fact that there isn't a control panel. For the last however long, Linux users have lived without a control panel. Since Linux (GNU/Linux, whatever) is an Open Source project, and the same with the WMs running on X, etc., it means that until recently, no one felt the need.

However - you feel the need. So, go build it. That's what it's about - contributing when you feel the system is lacking something. Have an itch? Scratch it, and submit the code. Go build one for Gnome or KDE. Don't give the excuse you aren't a programmer - here's a project to cut your teeth on. And I can't belive you don't have the time to do it - I've now seen this exact statment from you twice. The tools are free, so money isn't the issue.

So, basically, put up or shut up - if you want it, build it. That's how it works in an Open Source project. You won't see my name on any of the Linux projects - I've yet to feel the need for something within Linux (however, I have helped out on a couple other OS and free software projects. I just happen to have different itches to scratch.) Seriously - take up the project, design it, implement the inital code, and release it on the world - that's what it's all about! :-)

Re:No excuse - it's open source!

[aphr0]

And what about those who have the time but don't have any interest in learning the intimate underpinnings of the computer? Some people just want to use a computer, not program it.

Re:No excuse - it's open source!

[Mr. Slippery]

And what about those who have the time but don't have any interest in learning the intimate underpinnings of the computer?

They can pay someone to do it. They can either pay a vendor who won't open the source and will lock the customer into their proprietary system (and maybe even lure them into a subscription system), or they can pay someone to develop an open source system, possibly via a market like SourceXchange or CoSource.

Actually X can do it all!

[Wills]

As I posted below, the whole point of the color calibration stuff in X is it can handle color in a device-independent way by using CCCs (Color Conversion Contexts) to specify a display's color pecularities. Do your own monitor color calibration and simply load the calibration data onto your Xserver using xcmsdb. Once you've done that your example of specifying a device-independent foreground color in xterm using the CIE XYZ color space would give a properly calibrated color on your monitor. That's pretty useful. Your criticism of color management in X is inaccurate and misleading because you don't understand how to use it properly.

As a footnote, doing an accurate color calibration of a monitor, requires expensive test equipment like a tele-spectrophotometer.

Re:It's not a major priority now

[jspaleta]

There are no professional graphic designers or publisher that use Linux. Linux is not a platform meant for them. We need to focus on the strengths of Linux, instead of trying to create a jack-of-all-trades operating system like Microsoft Windows.

I disagree. Linux is the ultimate jack-of-all-trades OS. The openness of linux allows it to be what ever the users want it to be. Everything that is linux is built around someone scratching a personal itch. A lot of the software tools available first became available to add that one special feature one person wanted.

You might see linux as being a server-side solution, but who are you to say linux can't be a designers desktop solution too. Your imagination and skill might limit your vision for what an open source operating system can do, but your limitations shouldn't constrain anyone else. If someone wants to write the tools to make linux a publishing platform, they deserve our encouragement.

Linux is what we the users need and make it to be. To be sure, desktop publishers have been a small minority of the linux community, but if designers and publishers see potential in linux, there is no reason they should be told they shouldn't be working to turn linux into a tool they can use. -jef

Re:You didn't get it, did you?

[AFCArchvile]

I was pointing out that when Linux goes to the consumer side, then the party is over. Next time, read without the subjective judgment which you cherish more than your own life

Re:If Windows sucks so bad....

[Shelrem]

Umm... Macs have good color calibration, but Windows PCs don't. It's not that Linux is trying to be like Windows (although i think it is in some areas, and generally, those are the areas i stay the hell away from *cough*GNOME*cough*, but we will take good features, even if such features to exist in Windows.

Btw, show me one good feature that's in Linux that Microsoft came up with FIRST-- not before Linux, but FIRST. Please.

-benc

Wrong.

[Wills]

X, including all the free Xserver implementations, have had complete support in Xlib for doing color calibration -- see other posts here and here. The feature's been there since X11R5 which is years old.

cineSpace

[Anonymous Coward]

There is a professional commercial solution available from Rising Sun Research. https://research.rsp.com.au/index.cfm

You're wrong

[Wills]

Learn more about the full support for color calibration that is available in X here and here

Look for the Union label

[underwhelm]

Make sure that any color-matching plugin you use has Squant support.

Re:Look for the Union label

[CryoPenguin]

There's a problem with their RGBS pallete: there's no place that contains squant and blue and nothing else.

Re:Look for the Union label

[underwhelm]

That's actually a two-dimensional representation of a three-dimensional color chart.

Turn your monitor 90 clockwise to see sque.

Color Calibration fun...

[greenfield]

There has been some discussion about using nice monitors to get good color calibration. Unfortunately, good monitors are not the only issue. A good monitor may produce more precise color for a longer amount of time, but it may not be accurate. (Very few monitors are self-calibrating.) The idea behind color calibration is produce color that is both accurate and precise across a variety of devices.

The idea behind color profiling is that each device you use, input or output, has a profile. This profile allows you to take an image from the device specific color space to a neutral color space, such as XYZ or CIE Lab. Some devices come with profiles from the manufacturer, but if you want to get serious about color profiling, you must create your own profile.

One way to create a profile for a monitor is to buy a program that profiles your monitor using a colorimeter that you attach to your screen. For a printer, you can print out a series of color swatches and then scan in all of the color swatches with a colorimeter. (In short, a colorimeter is a very accurate color scanner.)

For example, say your monitor always has a bluish tint. When you profile your monitor, the colorimeter will "see" that more blue is always coming out of your monitor. The ICC profile that gets generated will have values that de-emphasize blue. Thus, when you install your ICC profile on Windows 98/2K or MacOS, the operating system will apply this profile to all images and colors generated from the screen and a more accurate color will be generated.

Printers are also interesting with respect to ICC profiles. Color printers are generally CMYK devices--not RGB devices. CMYK stands for the ink colors Cyan, Magenta, Yellow, blacK. ICC profiles for printers will convert to and from CMYK colors.

Color can be a tricky issue--I'm really glossing over a lot of important details. If people are interested in this issue, then can send me mail and I will try to dig up a reference or two.

Of course, what would a Slashdot posting be without some unsolicited advice? Most monitors come from the shop with the brightness all the way up and the color temperature at 9000 degrees Kelvin. This "looks good" the same way loud music "sounds better." Set your monitor to 6500 Kelvin or 5000 Kelvin and turn down the brightness significantly. Your monitor may seem more brown or yellow, but in reality it is a more neutral white. After time, your eyes will adjust to the newer whites and you will be happier. Also, if you turn down the brightness on your monitor, it will last longer!

Identical monitors/ Different colors

[ivan256]

I use two SyncMaster 900IFTs, and they match very well

I have two Dell P991 monitors(made by Sony) on my desk side by side but attached to different computers. (With x2x! Schweet!) The video cards in the two machines are both ATI RagePro but of a different chip rev. With the monitors at 1280x1024x32 100hz/80.2khz the color on one monitor is decidedly more blue then the other. It doesn't matter how similar or perfect your monitors are if the signal from the RAMDAC doesn't produce the same colors... All the more reason for digital interconnects I'd say, but untill then I'd kill for some color management!

Re:Identical monitors/ Different colors

[larkost]

hmmm... you say you want digital video out with color matching? hmmm... where have I seen a solution for that.. oh ya... Apple's ADC (Apple Display Connector) hooked up to a Apple Cinnema Display 22" Flatpannel. All digital connection, great picture, and Apple's ColorSync making sure that what you see is what you print. If you don't like the cost, well you can always go with the 15" flatpannel.

This is exactly where Apple is the domminent force, and has been since the orriginal LaserWriter

Re:Identical monitors/ Different colors

[ivan256]

Yep, those are sweet. Unfortunatly, one of them costs more then my whole setup... Oh well. Someday.

Answer: yes, fully supported in X

[Wills]

Here are pointers to info about the color calibration that is already built into the X Window System on Linux systems here and here

Re:Answer: yes, fully supported in X

[dead_penguin]

Hey Wills, you've been posting this to a few threads now. The info on xcmsdb seems to be fairly useful, but do you or anyone else know more about how to use it? A quick google search turned up little more than links to the man pages already on my system.

I'm just wondering-- how well does it work? Will it work with all apps making Xlib calls (i.e. essentially everything at some level of abstraction), or do apps have to be compiled with support? Are there decent utilities out there for setting this up, or do i have to play with the CLI interface to it?

Re:It's not a major priority now

[rigau]

That's interesting because i have used photoshop for 12 hours stright (no rebooting at all) on my wallstreet (266Mhz 192 ram --i.e. not nearly enough) laptop but i have seen PIII (600Mhz 256 ram) choke left and right on it. How much ram do you have on the G3? Anyway windows has nothing that comes close to ColorSync.

Re:You didn't get it, did you?

[pivo]

Oh, I was the one using subjective judgement? Just because you call any feature you don't personally want, "the consumer side" doesn't mean other Linux users, like myself, wouldn't welcome those features or that by having them Linux would somehow become useless ("the party's over") Maybe you should take that stick out of your ass before you post.

Re:It's not a major priority now

[NMerriam]

There are no REAL professional graphic designers or publisher that use Windows either.
They use macs because of ColorSync and because Photoshop actually runs much much better on macs.

Son, REAL professional graphic designers don't need colorsync, so it doesn't matter what OS they're on. If you don't know what a CMYK value is gonna look like without help from colorsync, you're not going to know WITH it, either.

Postscript is platform-independent, I've been using Windows for publishing ever since 3.1 (there was a time when any serious photoshop people were using OS/2 Warp to run Photoshop 2.5 because it was the most stable and memory efficient configuration on ANY system). I've meet plenty of Mac folks who don't believe it, but I've never met an imagesetter yet that disagreed with me...

---------------------------------------------

Calibration for visual effects

[rogerbo]

Linux is used by graphics professionals just not a lot in print yet. But in visual effects and in particular film visual effects, linux render farms are already common and linux graphic workstations are becoming increasingly common.

Most large visual effects houses have inhouse calibration tools that match monitor LUT's (look up tables) to film recorders so they are sure what they see on the monitor is what goes to film and gets projected.

An Australian company Rising Sun Research has just released CineSpace which is available on linux / irix and windows nt/2000. Never seen it so can't say anything about it but it's available here:
https://research.rsp.com.au/index.cfm

Java has excellent color management

[Olentangy]

The Java 2D API has excellent support for color management (I believe the code in the JDK is from Kodak) and can use ICC profiles. So Java programs running on Linux can have excellent color control.

See: http://java.sun.com/produc ts/ java-media/2D/index.html

-- michael

How about color _separations_?

[DG]

While we're on the topic, how about doing CYMK 4-color separations using Linux?

Can Ghostscript do this for you, or is this an end-user deal?

Links and advice highly appreciated.

Re:How about color _separations_?

[snowbike]

dvips will let you do this. From page 349 of the LaTeX Graphics Companion (great book!), the command to make the magenta postscript from a file called image.dvi is:

dvips image -h aurora.pro -h magenta.pro -o image-magenta.ps

Try kvidmode!!

[Moritz Moeller - Her]

It allows you to at least set the gamma mode of your display in KDE2. I use it, it is still in it's infancy, but at least a start.

Check it out at http://apps.kde.com/infofr.php?id=837Looks nice and might evolve to something great... I like it

Re: Not quite verbatim.

[AFCArchvile]

I made a few corrections to it; if you bothered to cross-check more rigorously, then you would've seen it too. Damn, if you missed that, then I'd hate to see your programming work; bugs everywhere.

I had RedHat 6.2, and I tried the CTRL-ALT-+ and - shortcut with my XF86Config file set to 640x480, 800x600, and 1024x768. In Windows, the ATI Rage IIC could hit all three of those with no problem, but the shortcut wouldn't work. I had to hack into the XF86Config file and delete the 640x480line. And that still didn't fix the colordepth problem: it was stuck at 8bpp. I knew that the card could handle 24, but X absolutely refused to comply. Don't accuse me of not trying, because I have. And my opinion is that Linux Stinks.

X has always had excellent color management

[Wills]

Get or measure some monitor color calibration data, and anyone can do full color calibration in X very easily and transparently in all X applications -- more details are here and here

Re:If Windows sucks so bad....

[pivo]

TrueType fonts? Ok, I had to think really hard but at least that's one.

Quick link

[omegawolf]

A quick search for "Linux color management" on Google led me to this web page.

Like the original poster, it appears this person has yet to find a solution, and may be starting a project.

To those that question the need, it truly is there. I'm a graphic designer by trade, and it is a major issue. Macintosh users (such as myself) have plenty of CMS resources, but I have yet to hear of anything for Linux.

Re:different versions of libc

[cthulhubob]

umm... why do you need old versions of libc?

The point of upgrading is because the newer version does stuff better with fewer bugs, right?

If you have binaries that are linked against older versions of libc (and you don't want to download new versions / recompile stuff), you can just make symbolic links from the correct library file to the name your application is looking for.

By the way, I think glibc-2.2 is coming out really soon (if it's not already - I haven't checked in a little while). ;)

From long experience ....

[taniwha]

I used to design graphics accelerators for Macs. Color fidelity/matching/whatever was a very big issue - marketting was very hot on it and we worked hard to do 'the right thing'.

The problem is that you can't satisfy everyone - even though you might be able to get it close to 'right' for one person everyone's eyes are different - the numbers of rods and cones vary widely enough that the way we perceive colors from phosphors and reflected from paper is different enough from person to person that you can't get it right, just close (for example at one extreme is the 10% of the male population who are red-green color blind).

Another example of this is the way that ambient light plays in our perceptions - colors can look totally different in the morning than in the evening in the same room because the color composition of the ambient light changes - people in publishing who are serious about this sort of stuff have 'white rooms' with known lighting and no outside windows to look at stuff in.

In my experience this area is enough of a sinkhole that you can/will get lots of competing schemes for color matching with lots of area for arguing - IMHO any color calibration system that doesn't calibrate for the individual user's eyes is worthless - but at the same any system that does so is so subjective that it can't be reliably measured.

Oh yeah - and look very closely at any system that performs liner math (multiplication, matrix ops etc) on gama corrected (logrithmic) pixels [hint almost any HDTV system that does picture scaling does this]

Anti-Aliasing and Translucency in X

[wfaulk]

There's actually at least some work being done on getting native anti-aliasing and translucency in X. Check out http://www.xfree86.org/~keithp/render/

Raph, interesting patent stuff there...

[Svartalf]

Went to your color management page, looked at the potential patent issues info referenced and have some comments that are germane to the discussion that you've started here. (And we ought to use the /. effect for good purposes in this situation... :-)

The Schriber patent (US4500919) seems extremely overbroad- may or may not be valid and seems to describe something slightly different than what we're looking for in a calibration system upon a detailed reading of what is exactly claimed in the patent. May apply, may not. Expires sometime in 2005 in any case.

The Walowit patent (US4941038) should probably be overturned- I've some nagging prior art suspicions on this one as it simply describes a system that does RGB to CMY conversion, adjusting for gamut differences in the original image and the target environ. (Now, where do I remember seeing code for that... Perhaps this one should be submitted for a bounty.)

The Arazi patent (US5212546) looks to be obvious (verging on common sense) and I'd think that it'd be covered by prior art anyhow (Wasn't Kodak or Fuji doing this sort of thing years ago, prior to the patent grant?)

(By the way, you might want to change the URLs to refer to 'http://www.delphion.com/' instead of 'http://www.patents.ibm.com/' as IBM's basically given the services to the Delphion IP Network...)

Colors?

[cluening]

I guess this is one time being somewhat color-blind makes things easier: I don't really care what the colors are as long as they look fine to me. Whether or not they look fine to somebody who can see them all normally is a completely different matter. :)

Re:Bouillabaisse Color Calibration

[Grendel Drago]

Umm... "Door Hinge"?

actually, most new RIPs...

[Mickey Squid]

actually, most new RIPs will do RGB to CMYK color conversion on the fly. Quark 4.11 will also do RGB to CMYK color conversion. So if Gimp doesn't do CMYK....who cares? Not me. (Prepress Manager by trade)

I give this guy credit...

[Fleet Admiral Ackbar]

for the username 'buttfucker2000'.

However, my friend, what will you do in forty days? Will you revert to vaginal/oral action, or will you spin a small threaded covering, wait a few days, and emerge, triumphant, as 'buttfucker2001'?

Re:It's not a major priority now

[chrischow]

REAL professional graphic designers

as opposed to a quiche eater? i dunno about you but my years of working in the advertising and design industries brings me to the conclusion that Mac rules well beyond all others. thats good. OS/2? i wish, thats the only OS i love more than the Mac but it simply wasn't that big a player. especially once PS 3.0 came out. layers baby. how did we ever do without 'em?!

WW III

[Mickey Squid]

I predict that the next great world war will begin as a civil war in the US and spread from there to the entire world. On one side will be the Unix factions including Linux, BSD and the new member MacOSX (yea, prolly beos too). On the other side will be all the various flavors of Windows. The war will begin as a Troll on Slashdot and slowly degrade to low level guerrilla warfare including cracking of servers, defacing company websites etc. The huge amounts of money involved will necesitate an escalation into all out warfare with the US Army being on the MS side and China monetarilly backing the Unixes. The only one's who survive in the US will be Quaker farmers in Pennsylvania.

I don't understand why this is important.

[DunbarTheInept]

I've seen these alleged color correction tools in Windows before, and I've always wondered what the point of them is. Who needs them? In what business or field of study (or video game) does it really matter that the color and gamma match exactly to what was intended? As long as they are close enough (i.e. magenta doesn't end up looking like green or something), then who cares? People are going to adjust their monitors anyway to match what the like to see, so the whole notion of gamma correction in software is pointless, as far as I can tell. In fact, I made the mistake of installing one of these things that came with a video card I bought, and now my games are all fu'bared and I can't adjust them back the way I like (and the tool didn't come with an uninstall option, so gettting rid of it will probably take some icky registry hacking as well as just deleting the files.) Is there some field of study or business I'm unaware of that really needs this kind of tool?

I'm not trying to be flameful - I'm genuinely confused. Obviously a market of some sort exists for these tools or they wouldn't keep making them, but I can't figure out what that market would be.

Re:I don't understand why this is important.

[chrischow]

well one major use is in publishing. you want your magazine you are designing in quark to look the same printed out. especially important when you are dealing with a company's corporate colour scheme and all that crap

Because the algorithms are proprietary...

[Anonymous Coward]

You can obtain the specs on ICC profiling at http://www.color.org/ but the algorithms are proprietary...

Interestingly enough, Silicon Graphics is a member of ICC, and perhaps an inquiry can be made as to a open/closed-source Linux/*BSD port of their color calibration software (BTW - Photoshop 2.5 was excellent on Irix).

However, as both M$ and Apple are also members of ICC, I'm sure both would object to any OSS port :-/

~AC

How can I (eweaver, question poster) contact you?

[eweaver]

I have monitor calibration data from Colorific on Windows for my Samsung. Could you send me your email address so I can get in touch with you if I have problems? It sounds like you know what you're doing.

Color Management

[Anonymous Coward]

If you want to get consistency in color, you need color management. In particular, you need all of the following:

1. System level support for a color management system (CMS) to drive your video display, printers, etc.

2. Accurate characterization of all your input and output devices, i.e., scanner, monitor & printer.

3. Support for CM in your application software.

4. Last, but not the least, the knowledge of how to use CM in your work.

For #1, Apple has Colorsync, and MS has ICM both of which are functionally equivalent (at least on paper). However, ICM is only available on Win 98 and win2K. If you are using Win 3.1, 95 or NT, you are out of luck.

For #2, you need specialized software and hardware to get accurate characterization (profiles) of your devices. For example, you need a spectrophotometer ($200+) to calibrate your monitor _and_ get an accurate profile.

#3 is obvious. All major graphic works from Adobe, Quark, Macromedia etc. can use CM under Mac OS. Support under Wintel is a bit spotty (See #1).

#4 is also important. My impression is that a large no. of graphics professionals still do not use CM anyway (steep learning curve, extra investment needed in hardware & software, reluctance to adopt new technology).

This should give you an idea of what is involved in getting good color out of a Linux box.

Re:It's not a major priority now

[NMerriam]

as opposed to a quiche eater?

I meant as opposed to folks on slashdot who "do a little work in Gimp now and then" or "I used to work on the school paper, and we used all macs".

i dunno about you but my years of working in the advertising and design industries brings me to the conclusion that Mac rules well beyond all others

Oh, certainly in numbers, Macs still are far ahead in the industry. My personal feel is that it has more to do with inertia than anything -- the same reason a lot of folks here say "oh, to do graphic design you need to use a mac". It's just "common knowledge" that you use macs for prepress, because of the historical development there.

As for OS/2, unfortunately it was only a year or so that it showed so much promise. We converted a LOT of systems to Warp when it came out, so that we could run photoshop on it, and it was fantastic -- I remember the Adobe Forum on Compuserve went nuts when PS3 came out because it wouldn't run on OS/2, and we kept begging IBM to get a win32 system going. The history that COULD have been, I suppose!...

---------------------------------------------

I wonder if Apple would GPL ColorSync...

[green pizza]

It would be "un-Apple-like", but it would make ColorSync even MORE popular. ColorSync is pretty much The Standard anyway and probably one of the few remaining reasons that graphic and layout artists continue to use the Mac OS over anything else. I've been hooked since the day I learned that I could download ColorSync profiles for my printer. The OS already had profiles for my monitor and printer. Very, very slick. Several of Apple's monitors of the past and present went even a step further, capible of doing a self calibration (if you don't mind waiting 2 - 5 minutes while the thing flickers and flashes and whatnot). For the truly hardcore, some of Apple's monitors have a setting where the system will recalibrate itself each time you finish fiddling with the monitor's brightness and contrast (most Apple monitors of the past 5 years have communicated with the computer via ADB or USB).

Food for thought.

X capabilities

[AlienCron]

X can switch video modes without restarting. X can do gamma correction. X can do TT etc. with XFS. Last I knew X had the libraries built by default for Alpha Blending but the X server does not use it nor do any other WMs aside from Tiny-X. Its in the CVS. Anyone who says otherwise obviously is not looking hard enough. Some men see things that are and say, "Why?". I dream of things that never were and say, 'Why not?". George Bernardshaw

Color calibration pisses me off

[Adam Wiggins]

Color calibration annoys the hell out of me, and I'll tell you why. Artists (and I've worked with many of them due to my years in the game industry) all think that it's their job to make sure their art looks the same on everyone's monitor. They think that if someone has their brightness turned down or otherwise has different color settings than wherever they originally created the art, that it looks "wrong."

Here's my complaint: the reason that you *can* change your monitor settings is that everyone has different eyes! My eye doctor always notes that my eyes are unusually sensative to light. When it comes to adjusting my monitor, I always want my brightness way down and the contrast at maxmimum. People always comment that they think things look "ugly" on my monitor because they are dark and high contrast; but I think that the settings that most people keep their monitors at are ugly because the colors look washed out and all the blacks look like dark grey to me.

There are a few places where color calibration is most certainly relevant (such as when your final medium is not a monitor, but a piece of paper, or something else), but most of the time you should just get it the way that you want it to look on your monitor and not worry too much about it being exactly identical on other monitors. (I do usually try viewing my web images with the brightness on my monitor turned up just to make sure that the blacks aren't too grey, but that's about it.)

Here's a question: anyone know how to turn off the use of gamma on a PNG? I love png's (smaller and more color depths than gifs) but IE and Mozilla both use the gamma setting and it ends up looking totally different from Netscape or a non-gamma'd GIF, even on the same monitor. My only solution so far has been to save the image as a PNG, quit the gimp, edit .gimp/gimprc to set gamma-correct equal to 0.4, restart gimp, load the PNG, and then save it out again. This results in the image looking pretty close to its original colors (that is, how it would look if I had just saved it as a GIF), but it's not exact. This issue is especially important when you're trying to make your image colors match that of the HTML-coded colors on your document.

Re:Color calibration pisses me off

[Glenn R-P]

Here's a question: anyone know how to turn off the use of gamma on a PNG? I love png's (smaller and more color depths than gifs) but IE and Mozilla both use the gamma setting and it ends up looking totally different from Netscape or a non-gamma'd GIF, even on the same monitor. My only solution so far has been to save the image as a PNG, quit the gimp, edit .gimp/gimprc to set gamma-correct equal to 0.4, restart gimp, load the PNG, and then save it out again.

pngcrush -replace_gamma .4 -ext _g04.png *.png

If pngcrush isn't already on your system you can get it from
pmt.sourceforge.net

Re:no color calibration in windows...

[chrischow]

OSX has colorsync too

Re:It's not a major priority now

[chrischow]

well its not just inertia, its also to do with the fact Macs suit the creative mind better. our creatives are mac guys and gals 100%. why? they just can't work with the way Windows works. PS on a PC sucks with its jerky MDI, thats IMHO of course

i think OS/2 is much closer to a Mac than Windows, in the way it works and stuff. its a real pity PS3 never was on the Warp OS, i could well imagine mixed OS/2 and Mac offices

Why have different versions of libc

[Wills]

Why do I want multiple libc versions of programs?
Because the net-present-cost of upgrading certain binaries outweighs the net-present-benefit.

Your suggestion of using links works in many cases for differentiating libc5 / glibc-2.0 programs but I haven't managed to get either it -- or the alternative of setting LD_PRELOAD -- to work for distinguishing glibc-2.0 / glibc-2.1 programs. For example, the commonest problem is the dynamic loaders ld-2.1.3.so and ld-2.0.7.so get confused about matching some symbol or other to the different versions of the shared libraries, e.g. _xstat even though LD_PRELOAD is telling the loader which are the correct Xlibs (2.1.3 or 2.0.7) to use.

Sexy fonts in XF86

[Aighearach]

Here is an example of sexy TrueType fonts in X, on linux. makeyourbanner.com. It also makes use of Gimp, and Perl. Kickass.

This whole article is crazy, though, colors will never "look" exactly the same on one computer as on another. Nor to one person as to another. Better is to just know what the fuck color #s you're using...

Micro HOWTO on color calibration in X

[Wills]

A quick search on Altavista for xcmsdb.c gives the untarred X source code (delete spaces in the URL by hand otherwise it won't open. If only slashdot would fix that bug. If only more sites would keep the whole untarred X). Look in the datafiles sub-directory therein for examples (delete spaces in URL) of the data formats used to specify the forward and inverse color-correction matrices. You can load one of the example files onto the root window using xcmsdb sample2.doc. Check the data loaded ok using cmsdb -query

Calibrated color is now set up!

Specify all your colors for any X program in a device-independent color space like CIE XYZ, and you'll automatically get calibrated colors on the monitor (assuming your monitor matched the data in sample2.doc). The colors can be specified by command-line options or in X resource files. To use the example of the previous poster, try xterm -bg CIEXYZ:0.371298/0.201443/0.059418 &. Leave that xterm running in the background. Remove the calibration: xcmsdb -remove. Start another xterm as before, and notice the slightly different appearance of the background color: xterm -bg CIEXYZ:0.371298/0.201443/0.059418 &. Ignoring the hard part of creating the calibration data, that's a quick tour of color calibration in X!

Re:Micro HOWTO on color calibration in X

[ywwg]

I get:

Could not find property XDCCC_LINEAR_RGB_MATRICES
Could not find property XDCCC_LINEAR_RGB_CORRECTION

Do not all drivers impliment this?

Re:Micro HOWTO on color calibration in X

[Raphael]

These messages mean that your display is not calibrated (no color-correction matrices have been loaded). If you get these messages before loading any profile (e.g. with xcmsdb sample2.dcc), then this means that your X server starts without any specific color characterization data for your device, but it does not mean anything regarding whether or not it supports this feature.

If you get these messages from xcmsdb -query after loading one of the example files such as sample2.dcc, then it is likely that your X server does not support color calibration. You should upgrade to a more recent version, if available... If you are using a commerical server that you cannot upgrade easily, then you should report this problem to your vendor.

For example, when I start a new X session (server: Sun OpenWindows 3.6) and I run xcmsdb -query, I get a message telling me that there is no XDCCC_LINEAR_RGB_MATRICES property, but there is already a XDCCC_LINEAR_RGB_CORRECTION property, containing RGB conversion tables for the visuals of the display. Some other servers (XFree86 3.3.6) start without any color characterization profile.

After running xcmsdb -remove on any display (regardless of the version of the X server), then I get the messages:
Could not find property XDCCC_LINEAR_RGB_MATRICES
Could not find property XDCCC_LINEAR_RGB_CORRECTION
because the profile has been removed.

When I run xcmsdb sample2.dcc followed by xcmsdb -query, then I get something like this (long tables snipped):

Screen: 0

Querying property XDCCC_LINEAR_RGB_MATRICES

XYZtoRGB matrix :
4.07591 -1.82044 -0.62731
-1.10248 1.93518 0.03736
0.05997 -0.20679 0.88572

RGBtoXYZ matrix :

0.33330 0.33724 0.22183
0.18946 0.70614 0.10440
0.02167 0.14203 1.13838

Querying property XDCCC_LINEAR_RGB_CORRECTION

VisualID: 0x0
type: 0
count: 3
Red Conversion Table:
length:256
0x0 0.00000
0x101 0.00000
0x202 0.00000
[...]
Green Conversion Table:
[...]
Blue Conversion Table:
[...]

If you get something similar, then your server is working fine. If you still get an error, then you should complain to your vendor.

there is no "accurate"

[q000921]

While color calibrationists are pushing the idea that there is some ideal notion of "accurate" that monitors can be made to conform to, the reality is much messier: color perception depends intricately on context, monitors cannot even begin to match the visual experience of real pigments and dyes, a wide range of "calibrations" are visually acceptable, and different people have different preferences and perceptions.

So, what should you do? Often, you can work reasonably well without more than a rough calibration. In fact, most critical color correction can be done completely in black and white--matching known colors (logos, skin color, neutrals) correctly is actually better and much more accurately done numerically than "by eye". Once you have established those anchor colors, you have a visual context, and you can fiddle with the other, less specific colors around them by eye without worrying too much about monitor calibration.

For on-line applications, you need to worry even less: none of your colors will display "accurately" on most machines anyway. You simply have to make sure that your images look OK on "average" PCs. While having a consistent starting point for designing those kinds of images is kind of nice, most good graphics cards and good monitors are probably going to be "in the ballpark" if they are reasonably well set up.

Maybe you really do need calibration for some of your applications; I have occasionally needed it for some really obscure work. But I think in many cases people want calibration for all the wrong reasons: for print work, calibration isn't accurate enough, and for on-line work, it doesn't help you much.

Color correction and dot gain

[psyklohps]

I work at a local newspaper doing page layout and graphic design. Let me tell you that color correction and dot gain are very important.

An explanation of dot gain is how much more or less saturated the color is going to be from the start of a project to finish. Lets say that you get an ad from a customer. First you need to turn it into an EPS from a PDF, then you print it to negative, burn the plate and then ink the plate and press it to paper. We have a 30% dot gain. That means that an area that is 70% black on the computer screen will be 100% black on press after all of the conversions; consequently 30% black will be almost white. If you can see what the colors are going to look like accuretly on screen then you will get a better printed product.

One time I worked on a project at home using the GIMP (RGB only) and then taken it to work, after the conversions to CMYK and the dot gain, the image looked like shit! So I only use the GIMP for web graphics. That really sucks because the GIMP would be a graphic powerhouse if it supported CMYK and if I could color correct X properly.

Now if we could only convince Quark to port Express and Macromedia to port Freehand I would never touch a Mac again.

Re:If Windows sucks so bad....

[jednet]

TrueType fonts were made by Apple.

Yes, it's useful and RTM

[Wills]

Your criticisms are very confused. The X Window System provides color calibration for displays (monitors). X is a networked graphics display system. X is not a printing system. If your printer driver does not support color calibration, you blame your printer driver supplier but you do not blame X because it's not the purpose of X to do printer color calibration.

You are confused about color calibration. If a calibrated chain of systems creates graphics output on a display device the output is only as good as the end-to-end calibration. Calibration can be done either by modelling each component of the chain and then composing the separate models, or by modelling the entire chain as a single black box.

In answer to your question, blame can indeed be apportioned!

• If a picture looks bad only on your monitor, blame it on your monitor's limited color space or your monitor's inaccurate color calibration.
• If a picture looks bad only on my printer, blame it on my printer's limited color space or my printer's inaccurate color calibration.
• If a picture looks bad even on a perfectly calibrated monitor or printer (hypothetical beasts of course), blame it on the picture scanning calibration.

In my opinion, X has all the color calibration features it needs; extras would make X bloated. Swapping pictures between Gimp and Photoshop is an application problem of converting file formats, not with calibration per se. Try asking Adobe for information about the file formats they use in Photoshop, then implement them in Gimp.

A quick explanation of X color calibration is here

Email me c/o ieee.org

[Wills]

You can email to William.Mackeown@ieeeNOSPAM.org after a few days when IEEE customer services will, I hope, have fixed my email account.

My micro HOWTO on color calibration in X is here.

For those who still don't get it

[FIGJAM]

This link might make you think of either how crapy your monitor is and/or how much color correction is necessary.

Interesting

[FunkyChild]

That's interesting..

Photoshop seems to run faster on my 266Mhz G3 at work, and the 350Mhz G3s at uni, much more than my K6-2/450. I notice an absolutely huge difference with Illustrator. The Mac version absolutely creams the Windows one.

Gamuts

[Anonymous Coward]

Term "gamut" comes from music; ask someone who knows music history. As used in colorimetry, I'm fairly sure it describes the range of possible colors. if, for instance, you try to create extremely vividly-colored images with really cheap watercolors, you just can't do it.

Similarly, even the best subtractive color dyes and pigments apparently just can't give a sufficient gamut by themselves; the three primaries-- yellow, magenta, and cyan, just aren't enough. (Nor do they collectively absorb well enough to create a true black, hence the addition of black.)

For that reason, the Hexachrome color printing process extends the gamut with (iirc) two more colors of ink (orange and a specific green, iirc).

Color gamuts of CRT phosphors can be rather good, but about 15 years or so ago, they couldn't get both a really good gamut and good brightness. High Fidelity magazine, long ago, had a fascinating article (complete with CIE chromaticity diagrams) about how color gamut in consumer TVs was sacrificed for brightness. (My Sony KV-1311 is extremely bright (has had little use), although I don't notice poor gamut. I do remember seeing very deep blues on a professional color monitor that I'd never seen on a commercial TV.)

If you care, try to get acquainted with the somewhat weird CIE chromaticity diagram (often, the colors shown are poorly done and only hint at reality). Probably no physical system can display the full CIE gamut.

You might also look into curves of light output (or absorption) versus wavelength; these can sometimes help understand matters. I suspect that computer monitor reds have a narrow-band peak, while the blue and green are broader band.

Maybe I'm just blowing hot air (figuratively!), but I suspect that really good correction might require some tweaks in the curves other than gamma and the simple operations.

--nb

Nicholas Bodley Waltham, Mass.

who sometimes neglects his e-mail for a spell... nbodley@world.std.com

gcms

[heby]

at least for printing there is gcms, the generic colour management system... check out http://gcms.sourceforge.net

Re:Bouillabaisse Color Calibration

[SealBeater]

porridge?

SealBeater

Re:You didn't get it, did you?

[bigchris]

You're kidding me, right? Colour calibration is a consumer thing? Don't make me laugh!

What about all those professional designers who need it? Converting from a CMYK colour space (terminology people?) to an RGB colour space is very important in the print industry!

If your that serious about ICC profiling X then,

[theflamingmoose]

The thing with color calibration is that it is really only for professionals. I recently worked with my previous work on color calibrating their photo studio. Color Callibration is a big bag of trouble in the least. If you really want X to be color calibrated I suggest you have a professional do it. A good person to speak to is Eddie Tapp. Eddie Tapp is with the Professional Photographers of America and is the nations renowned expert in color calibration and digital imaging. Take a look at his resume (and once you see companies like epson and cannon) and you will see what I am talking about.

Re: Get a Mac : why not ?

[pruneau]

I totally agree with you : but I think it might be the time now to give some attentions to those bells and whistles.

The real question is : should linux be a hacker-only OS, or not ? I do think not, because building your own gettho always was a way to die.

Hint : my favorite window manager is fvwm2, my favorite app is xterm.