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Grokking The Gimp
The Scoop One of the standout userland programs to come from Free Software development, the GIMP offers a powerful range of features for digital imagery. Unfortunately, not everyone's had the privilege of (or inclination for) sitting through 'Principles of Color' or similar classes. Not to fear, the author has - - and he's willing to share his knowledge.
Compounding the complexity challenge, the GIMP has its own way of doing things. Half of the work of editing an image seems to be making a good selection. Again, the author has theory to divulge and tips to present to improve your technique. Though only a few tools and methods are discussed, they are fundamental to all advanced operations. (Note that the book covers the as-yet unreleased 1.2 GIMP -- the 1.1.x betas have been quite usable for months.)
What's to Like? This attractive book is well-printed, with plenty of full-color images and good figures. It's also well-designed and the layout is excellent. The decision to add a few common problems and frequently asked questions at the end of most chapters is commendable. It's not designed as a reference book, but the index and table of contents are detailed enough to locate specific actions later.Banks assumes little prior knowledge of the GIMP. Chapter one is a brief tutorial of the program's features and functions. More experienced users can skip this, though I found a couple of timesaving tidbits. The same may be said of chapter two, on layers, though the material quickly moves beyond what an average user might discover in an afternoon. The selections and masks chapters form the real foundation for most GIMP work -- how do you choose parts of your image to edit? A little theory, a few tools, and some examples later, you'll have multiple answers for that question.
The next two chapters pile on the theory. First, Bunks discusses the theory of color -- running the gamut (so to speak) from additive to subtractive, RGB, HSV, CMYK, and grayscale. There's plenty of math (more than one would need), and the explanations here are quite detailed. It's fundamental knowledge, and most readers can probably pick up just enough to get by. Don't skip ahead and miss the very useful touchup discussions in chapter 6. (The author considers them worth the price of the book -- given the results on some of my images, I'm inclined to agree.)
The final three chapters each cover different tasks one might wish to accomplish. Bunks explores various techniques while creating projects. Screenshots and commentary accompany step-by-step instructions. It's in these sections that the full power of the GIMP comes into play. Rounding things out are a handy keyboard shortcut guide and a detailed index.
What's to Consider? Things do get pretty heady in the theory section. Non-programmers (and people who haven't already worked with professional imaging) will have some slow going trying to absorb the math and colorspace information. It's not essential to use the GIMP, but knowing the differences between the modes and the limitations of each is necessary for most serious work.Readers looking for a guide to the dozens of distributed plugins will be disappointed -- this book is more interested in the general techniques used in nearly every non-simple project. Finally, the book seems a little short. It's 342 pages, but the information is good enough that perhaps more subjects can be covered in a future edition. (That's a good thing.)
The Summary Nearly anyone will benefit from the deep magic behind the menu operations. Move past cheesy banners and poorly-executed lasso operations. Double the size and power of your toolbox, and get to know the GIMP. (If you're not convinced, browse the book online!)
Or buy it at ThinkGeek.
Table of Contents
- GIMP Basics
- Review of Layers
- Selections
- Masks
- Colorspaces and Blending Modes
- Touchup and Enhancement
- Compositing
- Rendering Techniques
- Web-Centric GIMP
- GIMP Resources
- Keyboard Shortcuts
FreeBSD (on i386) runs Linux i386 binaries very well, and glib, gdk, gtk+ gnome, gimp etc. run unber all BSD's, but porting gimp to OSX would be a lot more than just that.
For starters, gtk+ needs X-Windows, and Aqua isn't X-Windows by a long shot, so a port of GTK would have to be made (I'd be surprised if this wasn't underway, I know there was/is work on a BeOS port, and QNX photon uses its X layer to get GTK working..)
Anyway, this would certainly be a non-trivial port. Apple's not using X-Windows on purpose (personally, I think X gets a bad rap. I think it's great.) but I wouldn't hold my breath for a GIMP port. Command-line stuff probably compiles cleanly, but something as complex as gimp....
A GIMP expert has to choose between "giving away" improvements that make GIMP better by patching the UI, or writing a book and making a quick buck.
This is an interesting viewpoint, but I disagree.
I code a little, mostly PostScript, though I can do a little C. I've also written two books in Samba.
My choice was, practice coding and networks and NetBUIE for a few years to make a meaningful contribution to Samba, or spend six months writing a book on Samba. If I had chosen the first route, I'd still be coding and practicing, and hoping someone on the Samba team would notice my patches.
Also, not every good coder is a good writer, and not every good writer is a good coder. To be a good writer, you need to write to the level that other people can understand, especially if they don't have your level of knowledge. To be a good coder, you just have to code so that your software works, and other coders can work to understand it. My coauthor helped me out immensely in making my second book readable, precisely because she is not a Linux guru, once she could understand a concept, your average person looking to implement a Samba server should be able to understand it.
Thanks,
George
I know about LinuxArtist.org and CreativeLinux.com. Are there any other good sites that specialize in news about Linux tools for creative types? Things like GIMP, Broadcast 2000, HTML editors, etc...
Webmaster www.streetrodstuff.com
> I can do my editing twice as fast with Gimp than I can with photoshop.
I pieced together a 6200x6200 pixel grayscale aerial photo of Berkeley, CA with images from Terraserver. There were brightness/contrast differences between tiles I wanted to manually tweak.
Editing that image sounds like a big job. But, representing each pixel with a byte (because it's grayscale), the image is 38.4MB. Since I have 128MB of RAM, I thought editing it in Gimp would be feasible. Nope, it just thrashed my swap space. Note, I had to go to a machine with 256MB of RAM just to merge the tiles using ImageMagick.
For the same file, Photoshop performed exceptionally well. For instance, it quickly loaded the image and allowed real-time arbitrary zooming and panning. Of course, I also fixed my brightness/contrast issues. If I took the time to figure out how to batch-append those tiles using Photoshop, I assume it would have been significantly faster than ImageMagick.
Kudos to the Gimp team for building something that is both usable and something people enjoy using. But, I'm getting tired of people proclaiming various open source projects as being superior applications than their commercial counterparts just because they're looking at them through Open Source Beer Goggles. Evaluate the application on its merits, not on its religion.
I suppose I'm peeing into the wind asserting something like this on Slashdot... c'est la vie.
>on what grounds Photoshop or some other
>proprietary package might still be superior to
>our beloved GIMP?
Sppeaking as a Linux/Mac/Vider/Graphics geek who worked on the newspaper whilst in college; and who made the mistake of mentioning this at my previous job, and wound up getting loaned to the design dept as the resident Mac guru as a result...
The GIMP is a fine little tool. I use it a lot...
... for WEB graphics!!!
>One thing I *have* heard is that GIMP is poorly
>equipped for print media. This has to do with the
>GIMP's limited support for non-RGB color
>palettes.
You have heard 100% correct sir. If you're ever going to commit to hard copy, the GIMP (as well as paint shop pro and the like) is absolutely WORTHLESS.
If you ever plan to PRINT your work to PAPER (and not have it look like crap) you MUST have a tool with support for: CMYK, Pantone colors, and COLOR CALIBRATION!!!
And I can't emphesize enough the importance of color calibration. Without it, you can be pretty much assured that the work you get printed will in no way resemble the work you submitted; your colors will be off not only between monitor and printer, but from computer to computer as well. And forget color calibration that involves "hold this card up to this square on your monitor and enter the number of the closest match". If you're going to print your work, you *MUST* have HARDWARE calibration!!! I've only seen a total of TWO calibration schemes that are worth more than a cup of warm piss. Those schemes are those of Apple Computer, and Silicon Graphics (big suprise, eh?).
>My understanding is that virtually no one in
>the print world uses RGB palettes.
Correct again. RGB are your component LIGHT colors; fine for web work where you can be sure that most ppl are viewing it on a shitty, non calibrated monitor. If you commit your work to PAPER, you use CMYK or Pantones. CMYK are the component colors of PIGMENTS... used if you're printing something like a photo, with MANY colors. Pantones are custom colors mixed in large batches... used if you're doing a large run of a product with FEW colors, like corperate letterhead w/ logos, etc.
Hope this helps.
john
Resistance is NOT futile!!!
Haiku:
I am not a drone.
Remove the collective if
Imagine all the people...
This page has a link to several Gimp books:
http://www.xach.com/gimp/books/
I've got the "Gimp Essential Reference" myself, and find that it's by and large an excellent book. Before this book, I didn't really understand layers.... My one complaint is that the chapter on writing scripts and plugins is sketchy enough that it should be presented as more of an introduction. Additionally, with the intorudction of Gimp-Perl, I expect more people will want to use that than the Scheme language which is the default described in the book.
-RobTexts on open source projects are great; they are a way for some people to generate revenue, and support the wider user base who doesn't want to have to work on the project to understand how to use it.
There is a tension that is not (as) present in commerical software, however: selling support and manuals vs. improving the interface to the product. Adobe sells PhotoShop for $600-$900. They'd rather keep the software ideal and not sell you a manual.
A GIMP expert has to choose between "giving away" improvements that make GIMP better by patching the UI, or writing a book and making a quick buck.
-m
Also groovy was when she tried random Photoshop commands such as CMD+click to do things with the bezier curve (I'm not a real gimp gear-head so ymmv) and other tools, and they worked!
Within minutes she was totally at home w/ the GIMP. Most keystrokes are the same, or a substitution of ALT for that "apple" key. The other factor on the learning curve was geting used to having 3 buttons instead of 1 on the mouse.
In short, people who are reluctant to switch from 'safe' mac to 'tecchie' linux should take some heart from the near total portability of knowledge between photoshop and the GIMP.