Implementating Transparent PNGs in IE7

Brandon writes "Over at the official IE Blog, Sam Fortiner has posted some very detailed information regarding Alpha PNG Rendering in IE7. From the article: 'As the dev who implemented the support, I can state that it was neither a bug-fix nor did it require a re-write of the display engine. Instead, it ended up being somewhere in-between the two and required what I would call "feature work." Implementing transparency support for PNG images required a significant amount of modification to the image decoding and display pipeline in IE along with a significant amount of new functionality added to the PNG decoder.'"

Comments

libpng....

[__david__]

So this implies they wrote their own PNG reading routines instead of using libpng?

Is this some sort of NIH thing?

libpng has a BSDish licence if I recall... So that can't be the issue...

-David

Re:libpng....

[Chris_Jefferson]

If you read the article, you'd find the main problem is that all their internal data structures and rendering system were only designed for boolean transparency.

libpng wouldn't have helped with either of these, and this is where most of the work was.

Re:libpng....

[Quarters]

When Microsoft puts BSD licensed TCP/IP code in an OS people use it as a cheap opportunity to sound psuedo-intellectual by bringing it up in vague "Microsoft is bad because they didn't write their own" terms whenever possible.

Now those same people want to say "Microsoft is bad because they didn't use BSD licensed PNG code."

The hypocrisy is staggering.

Re:libpng....

[eraserewind]

Um, it's only hypocracy if the same person says it.

Probably because IE displays images as they load..

[cwensley]

I'd imagine this would be why IE can show images as they download, instead of waiting for the whole thing to download like other browsers...

I could be wrong..

Monopoly

[augustz]

This is a really interesting case study in monopoly behavior and the value of competition. Microsoft you will remember pretty much stopped IE development and shut down the IE team.

Firefox came along, and whamo, all of a sudden Microsoft has developers writing things like. Very impressive. What's interesting for me is they are huge huge company by comparision to Firefox, but it took firefox to really get them to start making some improvements.

You are

[leonbrooks]

Konqueror displays partial images as they download. The original friggin' browser in OS/2 did the same thing. It's hardly new.

Think about it: what's the whole purpose in Progressive-mode JPEGs?

Implementating?

[Atrax]

put your spellchecker on danger money, baby.

Re:Implementating?

[abulafia]

Naw, they're just misoverestimavating the submittzors.

Re:Implementating?

[Stephen Williams]

What's the problem? It's a perfectly cromulent word.

</obsimpsons>

-Stephen

Re:Implementating?

[NanoGator]

"I think it's time I spent my precious picoseconds looking at some other website."

If typos are such a sore spot with you, why come down into the forum area of Slashdot?

Reading between the lines of the story...

[leonbrooks]

...the code they're rewriting has not been substantially changed since the days when GIF was king of the images.

AFAICT, what they've finally added is genuine translucency (not the simple yes/no transparency of yore) to MSIE's image handlng.

Does anyone know of any other (non-text-mode) web browser which hasn't already been doing translucency for years?

Re:Reading between the lines of the story...

[jericho4.0]

"Obviously, if it wasn't a 'deep' problem, tney would have supported transparent PNGs years ago."

The PNG support seems to have been done by one guy, in a few months. Not exactly a 'deep' problem for a company with Microsofts resources.

I think the reason they didn't support it years ago is because they simply don't care.

Implementating?

[eric.t.f.bat]

Implementating? Implementating???!!!

Something is very very wrong with the /. editors. I think it's time I spent my precious picoseconds looking at some other website.

Requires IE5, IE6

[julie-h]

I have a question. When there is written

"Requires IE5, IE6, or better"

on a website. Does that mean Firefox?

Re:Requires IE5, IE6

[FidelCatsro]

to me "Best viewed in Microsoft Internet Explorer" say "Wanted , new web designer/Developer"

Re:Requires IE5, IE6

[Baron_Yam]

As an extremely crappy web site maintainer (I maintain a moderately unimportant site as the last and least significant of many duties)...

The first thing I did on taking over the job was convince my boss that I needed to install Firefox and a Tidy-based HTML validator to ensure the site had been coded correctly... it wasn't. Several things didn't work properly, and a few things here and there just didn't load at all.

Now that I have Firefox on my PC, I use it by default, and pop up IE to check the site for IE compatibility. Firefox is just a better freakin' product, especially with my four or five fave extensions.

Re:Requires IE5, IE6

[FidelCatsro]

IE is a complete pain to code to , I have it installed on my Mac just for testing compatability if i ever feel like doing any web stuff.
I end up making a php checker page sometimes to just redirect people to a striped down non complient page if they are using MSIE.
Well thats ok for me , most of my stuff is for Unix type OS or mac so there isn't really much alternative , though i have got complaints from people whop use IE saying my site is broken , the reply is awlawys (if they are using MSIE) "No your browser is", Simple as that... though most people dont really have an option like that.
The only awnser has been to code in some javascript check to alter parts of the page based on the browser . ;) When i was working as a web dev , there were days when i felt like taking a flight to the MS offices and going "Standards complient " on the IE team.

Fixes

[Adelbert]

So IE7 will show transparent PNGs, Firefox 2.0 will render /. properly. What will I be able to complain about then?

CSS support?

[tryone]

Very nice. Now go fix the crappy CSS support.

Re:CSS support?

[Nevyn]

You need to specify "display: inline-table;" for the table element.

Re:CSS support?

[Enrico Pulatzo]

Are you trying to break CSS with your markup there, or do you have a legitimate reason for making a table display inline? When you make an element inline and force it to contain non-inline children this kind of thing happens. It'd be the same as wrapping a table with a span and complaining that the span isn't being applied correctly.

Png, schming

[the eric conspiracy]

Now that the LZW patent has exprired, whoop-de-doo. Where were they when we really needed good png support?

What we need now is something that isn't a petri dish full of a rich agar browth waiting for every sort of web infection to take root and mulitply to the destruction of your computer, and something that adheres to CSS2 standards. But we already know that these needs aren't going to be met, so all I can draw as a conclusion is IE7? Bugger off. Waste of Time. Non-starter. Count on using Firefox for the foreseeable future.

You underestimate the power of PNG

[Anonymous Coward]

Besides the fact it generally offers better compression, now that we have FULL transparency in IE7, we can start doing some really great things with overlaying images in styles and such. Too bad it'll be like 2012 before IE6 disappears.

[OT] I just want to know why...

[leonbrooks]

...when Conan32 spelt "hypocrisy" correctly, and both eraserewind and NanoGator had it right there on their screens to reply to, they both spelt it wrong?

<thwack!>