An Overview Of PNG; Mozilla M17 (Updated) 221
PNG, MNG, JNG and Mozilla M17
26 June 2000
by Greg Roelofs
PNG support in Mozilla has improved greatly over the last few releases ("milestones"), and with each milestone comes a corresponding Slashdot posting and a lot of discussion. Unfortunately, not all of the discussion is entirely accurate, so here's a preemptive posting that attempts to update folks on the status of PNG support in Mozilla and other apps and to clear up some of the more common misconceptions. (This seems to be an annual event...)
Home Page
First of all, the PNG home page got booted off of cdrom.com in early March, and in early May it settled into what should be its absolutely final home:
This is currently hosted on freesoftware.com, Walnut Creek CD-ROM's new site for free software (quel surprise!), but if something should ever happen to Walnut Creek, libpng.org will be redirected appropriately. (On a related note, the new zlib URL is http://www.info-zip.org/pub/infozip/zlib/, which is also currently hosted on freesoftware.com.)
PNG Features for the Web
Insofar as this is ostensibly a Mozilla posting, let's have a brief rundown of the PNG features that are most useful to Web designers:
- alpha transparency - This is geek jargon for partial or variable transparency, and it lets you do nice effects that are independent of the background color(s), such as antialiased (non-jaggy) text, drop shadows, gradient fades, and translucency. PNG not only supports a full 8-bit alpha channel in grayscale and RGB images but also what amounts to an "RGBA palette" in colormapped images. The latter lets you do nice transparency without a huge hit in file size. For example, all but one of the transparent images on my PNG alpha-transparency test page are 8-bit or less; the lone exception (one of the toucans) is a 32-bit RGBA image, virtually indistinguishable from its 8-bit cousins. Note that PNG supports only unassociated (non-premultiplied) alpha, since the alternative is not lossless.
- gamma correction - Gamma allows you to display the same image on different platforms without looking too dark on some and too light on others. For best results it does require that both the designer's display system and the user's be calibrated, but even educated guessing is better than nothing in a viewing program (which is what Mozilla does). Warning! Watch out for Adobe Photoshop; version 5.0 had a serious factor-of-two bug in its PNG gamma support, and 4.0 also had some problems. (Things seem to be fixed in 5.5, however.)
- color correction - Where gamma has to do with image "brightness," color correction has to do with rendering shades of color precisely. PNG supports it, but not many applications do; it's pretty tricky to get right. Note that Photoshop 5.5 writes incorrect PNG "iCCP" chunks, and this will crash applications based on libpng 1.0.6. (Older versions of libpng ignore the chunk, and the soon-to-be-released libpng 1.0.7 will work around it.) Also note that feeding a valid iCCP chunk to PS 5.5 will hang it.
- compression - A lot of people have some seriously crazy ideas about
PNG's compression. Here's the straight dope:
- PNGs tend to be 15% to 20% smaller than equivalent GIFs on average. There are some GIFs, particularly 32- or 64-color ones, that are smaller than the best PNGs, but usually by only a couple of percent. There are also many that are more than twice as large as the corresponding PNGs, but these tend to be tiny images. (One exception is this image, which is dimensionally rather large yet only 1/3 the file size of the GIF version.)
- PNGs tend to be much larger than standard JPEGs. JPEGs are lossy, while PNGs are lossless; for natural (photographic) material, no lossless format can compete with JPEG--PNGs will typically be 5 or 10 times as large. On the other hand, for simple graphics or text-filled images with relatively few colors and sharp edges, JPEG is much worse, both in quality and in file size. (This means you, Slackware guys!) Use the proper tool for the job--no single image format is best in all cases.
- PNG is roughly comparable to JPEG-LS, the new lossless JPEG standard. On the Waterloo BragZone test suite, JPEG-LS beat PNG by 5% to 10% on natural images, but PNG beat JPEG-LS by 35% to 270% on "artistic" images. YMMV.
- PNG's compression method can be implemented in such a way that it is completely free of all known patents, but it can also be implemented in such a way that it infringes on patents held by PKWARE, Stac and others. You can guess which way zlib was written. Folks who are neither rich nor expert in patent law should probably stick to zlib- and libpng-based implementations.
- Unlike (LZW-based) GIF, in which the compression is basically deterministic--that is, you end up with pretty much the same data regardless of who does the compression--PNG's scheme leaves a lot of room for optimization. Some programs do a good job, some don't. The GIMP happens to be one of the good ones, as is pngcrush. Photoshop traditionally has been one of the not-so-good ones, although version 5.5 includes a "Save for Web" option that presumably invokes ImageReady. ImageReady 1.0 was mediocre and reportedly isn't much better in its current release (i.e., pngcrush beats it by 15% to 25%), but it is better than Photoshop's normal "Save as" option.
- The compression engine can't help clueless users who perform apples-and-oranges comparisons. If you start with a truecolor image and save it as both GIF and PNG, chances are the PNG will be 24-bit while the GIF will be 8-bit. Guess what? It's pretty tough to overcome that initial 3:1 deficit, no matter how good your compression engine is. (If you're not sure what kind of PNGs you have, check!) Also don't add a lot of text annotations to the PNG--unless you do the same to the GIF--and especially don't add a useless alpha channel to opaque images! (That last is directed at the Burn All GIFs folks...) Recompressing an image after it's been through JPEG compression is also a bad idea; JPEG leaves a lot of nasty little artifacts (often invisible to the naked eye) that screw up non-JPEG compressors.
- interlacing - PNG's interlacing scheme is two-dimensional, much like progressive JPEG, but unlike GIF--which uses a one-dimensional, line-based scheme. The upshot is that an interlaced PNG with text in it will be readable roughly twice as soon as the corresponding interlaced GIF.
- animation - Nope. But see MNG, below.
- MIME type - image/png. If PNG images on your server show up as broken images within Web pages and as gobbledygook text when referenced directly (i.e., as standalone URLs), you probably don't have the MIME type set up correctly. On the other hand, if they show up correctly for MSIE and some versions of Netscape but not others, you're probably running Microsoft's IIS server. Technically it's a bug in older versions of Netscape (versions 4.04 through 4.5), but consider switching to Apache anyway...
- browser compatibility - We'll get to that in a moment.
PNG Extensions and the Future
PNG is extensible. PNG is lossless. PNG is a single-image, raster (bitmap) format. One of its overriding design goals was backward compatibility. As a result, don't expect to see any sort of lossy compression methods (JPEG is doing a fine job of that, with the exception of transparency--but see JNG, below). Also don't expect to see any vector-based extensions--SVG with gzip content-encoding has that covered. Indeed, don't expect to see any new, incompatible compression methods for quite a while. Until there are lossless methods that can, on average, halve the size of PNG images, the cost in software compatibility is far too great. (Keep in mind that there still browsers that don't support progressive JPEG, and that was a relatively trivial change! And let's not even talk about JPEG 2000...)
PNG is also not going to become an animated format. Leaving multiple-image support out of PNG was a conscious design decision by the PNG development group, and it's still the right decision. Overloading a still image format with animation or video features merely confuses users and Web browsers, which have no way to distinguish still images from animations without prying into the data streams (which usually means downloading them first). Developers who prefer to program monolithically can always program for MNG instead; it's architecturally identical to PNG, and PNG is a pure subset of MNG.
Related Formats
MNG: As the previous paragraph suggests, the animated version of PNG is called MNG, for Multiple-image Network Graphics. It supports looping (including nested loops), clipping, deltas, and other features, plus everything PNG supports--including alpha transparency, of course. The home page is here:
Since this spring, a free reference library, libmng, has been under development by Gerard Juyn; its home page is at:
Note that the MIME type is video/x-mng; it has not yet been registered with the IETF. Undoubtedly there will be many misconfigured Web servers in coming years...
JNG: JNG is short for JPEG Network Graphics and is a proper subset of MNG, just as PNG is, but it's worth a separate mention. The idea is to combine the best of both worlds: JPEG's excellent compression and PNG's incredibly spiffy alpha transparency and color correction. JNG is almost identical to PNG, but in addition to standard IDAT chunks (which in JNG contain the alpha channel), there are also JDAT chunks that contain a standard JPEG/JFIF stream (suitable for handing off to libjpeg). From a developer's standpoint, if you've got support for both PNG alpha and ordinary JPEG/JFIF, adding JNG is a breeze. Of course, JNG is also supported by recent libmng betas. Its MIME type is image/x-jng.
Browser Status
Most browsers have supported PNG since at least late 1997 (when Netscape Navigator and Microsoft Internet Explorer finally did), but almost without exception, their support for alpha transparency has been abominable. Amazingly enough, it seems that 2000 may be the year that browsers finally support it, more or less ubiquitously. In April alone there were three newcomers, with another in May; so far this year, the total has more than doubled. Here's the current list of browsers that at least attempt to do alpha transparency correctly, with their supported platforms indicated in italics. If screen shots of the PNG alpha-transparency test page are available, they're linked to the browser name:
- Arena (Unix/X) - this was the first browser with good alpha support (at least for Unix, and I think anywhere). It died in 1998, however, and the final release tends to core-dump on PNG images. It always used its own "sandy" background pattern rather than that specified in the HTML. (Very old screen shot.)
- Browse (RISC OS) - Acorn's browser was the first to fully support PNG transparency and gamma correction, including background images, but it died along with Acorn itself in June 1999. The browser may or may not eventually show up in Pace Micro's digital set-top boxes. (Very old screen shot.)
- iCab (Macintosh) - this was the first Macintosh browser to support alpha transparency (since the 1.8 beta), but it doesn't do gamma correction yet.
- ICE Browser (Java) - ICEsoft's commercial browser for Java reportedly has full alpha support, but I haven't verified that.
- Internet Explorer (Macintosh) - version 5.0 added superb PNG support, including alpha, gamma and color correction. This is probably the best PNG-supporting browser available today. Unfortunately, the Windows and Unix versions seem to be a completely separate code base, so there's no telling when (or if) they'll have equally good support. (See the browsers page for details.)
- Konqueror (Unix/KDE) - I just heard that KDE's file-manager-cum-browser has full alpha support, but I haven't had a chance to check it myself. I'll try to get some screen shots added soon, however.
- Mozilla (Macintosh, Unix/X, Windows) - alpha was enabled in April, though there are a few gotchas: the Windows code is currently broken (bug 36694 and 19283, to be fixed by beta3), and the X code is a slightly nasty hack--it looks beautiful on 24-bit displays, but it's slow when scrolling, and the quality for users of 8- and 16-bit displays will be relatively poor. Nevertheless, it's a vast improvement over the previous code, and it's basically the only game in town for Unix users. Note that the infamous PNG interlacing bug (3195) was fixed in May, and Tim Rowley checked in initial MNG and JNG support on 12June.
- NetPositive (BeOS) - version 2.2, released in April, added support for alpha transparency; but like iCab, it doesn't yet do gamma correction. (It also doesn't display interlaced PNGs progressively.)
- Netscape - see Mozilla (which is basically what Navigator 6.0 will be).
- Sega Dreamcast Web Browser (Dreamcast) - version 2.0 of Planetweb's browser for the Sega Dreamcast game console, released in May, fully supports alpha transparency, but I don't have any screen shots yet.
- Webster XL (RISC OS) - R-Comp's RISC OS browser is claimed to have full alpha support, but I don't have verification, and it doesn't appear to be under development anymore.
- WebTV (WebTV) - surprisingly enough, WebTV has decent support for 32-bit RGBA PNGs, but its support for palette transparency is broken. In principle it should be easy to fix, but then again, it's a strange platform. (Note that the fonts look considerably better on a television screen.)
Honorable Mention goes to Siegel & Gale's PNG Live plug-in for Netscape, which was the only plug-in ever to manage alpha transparency (in Windows only). It died before ever getting out of beta, though, and plug-ins in general are useless for PNG. So is the HTML 4.0 OBJECT tag, but don't get me started...
Other Apps, Libs, etc.
I currently list some 500 distinct PNG-supporting packages (more if you break things like Microsoft Office into their constituent parts) in 8 categories (soon to be 9 or 10), not to mention a dozen pieces of hardware. PNG has now reached the point where even freeware authors generally don't bother to tell me when they've added support; it's largely taken for granted. (I do occasional Freshmeat sweeps, but I usually don't have time, and many entries don't mention PNG even if it's supported.) Quite a number of the apps include full source code, by the way--which is the way it should be, of course. ;-)
Within the libraries-and-toolkits category, there are a surprising number of independent PNG implementations (either encoders or decoders or both), including ones in C, C++, Java, JavaScript, Pascal, and even Ada95. PNG is now a standard part of Java 2 SE 1.3 and Tcl/Tk, and it is the main image format in the popular gd library and all of its Perl-based derivatives. In turn, this has led to its online use in areas as diverse as server statistics, chemical diagrams, computer-generated mazes, and weather maps.
Even better, PNG is the native, internal image format for a number of major applications (including Macromedia Fireworks and Microsoft Office), and it's becoming a popular icon format for advanced GUIs. It also ships as a standard part of BeOS, via the Translation Kit, and it's supported natively in the Windows Me shell (and possibly in Windows 2000 Professional).
Conclusion?
Ordinarily I'd mumble something about how PNG has finally achieved massive studliness and will soon be taking over the world, but what the hell--it has, it is, and if it's not obvious from what I've already written, another couple of lines won't make any difference. Go forth, visit the web site, write code, make lots of PNGs, etc., etc.
And Microsoft, pleeeeease get on the ball with Internet Explorer for Windows and Unix...
M25 (Score:5)
Mozilla (will be) release(d) (Score:4)
Maybe I'm just reloading too often.
Smells Like Troll Spirit (Score:3)
They're fun to pour right down your pants
Natalie is naked and turned to stone
Oh no, OOG's gone, now I'm all alone
Hello, hello, hello, Katz blows
Hello, hello, hello, Katz blows
I like trolling, it's contagious
Here we are now, moderate us
You don't like caps, post aborted?
ASCII art plans, they are thwarted!
I got bitchslapped, I dissed Bojay
I post flamebait every Troll Day
Yeah!
First posting's what I do best
And for this gift I feel blessed
Commander T likes other men
And always will until the end
Hello, hello, hello, Katz blows
Hello, hello, hello, Katz blows
VA's stock price, it's disastrous
Hey, does timmy ride the short bus?
All they post now: Lars and Napster
Well, this sure ain't stuff that matters
Raymond shoots ten who don't 'get it'?
Read it Tuesday on ZDNet
Yeah!
And I forgot
Just why I post
Oh yeah, I'm first, so now I can boast
I'm not that lame, the filters are blind
Can you imagine a -- oh, nevermind
I'm not rabid, like the zealots
So they flamed me, they're just jealous
Metamodding and IP bans
Won't you use them on ol' sorehands?
I don't want to beg for karma
Don't hate patents, just your dogma
I'm not insightful
Not insightful
Not insightful...
Yu Suzuki
So how well does it REALLY work now? (Score:2)
I'm considering installing Mozilla on my FreeBSD box and using it as my regular web browser. I've heard nothing but good things about it, and even if half of them are true this browser will kick serious arse.
But really, I'd like to know from an actual user of Mozilla: how stable/fast/featureful is it in its current incarnation? Is it usable as an everyday, workhorse browser, or is it still not for the faint of heart? That is, compared to my current browser, Netscape 4.7, which hasn't been too reliable of late.
Mozilla on Linux (Score:1)
Re:M25 (Score:1)
Mozilla Vs. Netscape (Score:1)
I know it will be just a matter of time, but I certainly wish that they would be quick about it. I'm getting hives from using Netscape. Motif truly blows.
JoeLinux
Re:So how well does it REALLY work now? (Score:1)
On the other side.. Like Netscape Mozilla has a habit of crashing every now and then, and the most annoying bug (??) in the browser is that it doesn't remember where you were on a page when you clicked a link, so when you go back, it's on the top again (try it with freshmeat, it's annoying). I hope they fix that soon!
Re:So how well does it REALLY work now? (Score:1)
Re:So how well does it REALLY work now? (Score:1)
Mozilla M17 - No It's Not. (Score:5)
Come on slashdot, this happened before with M16 as well, it was released way after slashdot said it was out. didn't you see it coming this time?
less irresponsible 'Mnn is out!' posts please. how would you like it if someone said 'hey look you've finished!' even though you'd just started. wouldn't be a true indication of the finished product would it.
I'll stop ranting now..
That's cool but... (Score:2)
In other words, M16 has been released, the nightlies are now M17, once M17 milestone has been released, the nightlies will be M18, until M18 milestone is released, etc
Re:PNG & MNG Support? (Score:1)
People really amase me, sometimes.
This message was edited by ``Self Censoring Keyboard++'', proud member of ``Living Politely Suite''
---
More articles like this, please (Score:1)
Re:PNG & MNG Support? (Score:1)
I'll have to get myel one o thoe. The one I have here prevent wearing and proanity by diableing ome of the letter key.
When will the final version of Mozilla arrive? (Score:1)
IMHO IE 5 / 5.5 still is the best browser around, to bad Microsoft won't relase a Linux version (or will they, after the ongoing battle with DOJ).
The internal MS geeks probably have a Linux version of IE allready =).
regards,
Re:WARNING: Link leads to goatse.cx (Score:2)
Cheers,
Tim
Re:PNG & MNG Support? (Score:2)
What the HELL are you talking about?! (Score:1)
Secondly, all the fancy PNG features mentioned in this article were working quite nicely as of M16.
Re:So how well does it REALLY work now? (Score:1)
Re:When will the final version of Mozilla arrive? (Score:4)
Plus, Netscape has had print preview since before 1.0. IE added it in what, 5.5?
I'll admit, IE 3 was better then Netscape 3. And Netscape 4 has it's problems as well, but IE went the wrong direction once MS played around with it for 3 versions.
Re:So how well does it REALLY work now? (Score:1)
Phooey! (Score:1)
If only!!! (Score:1)
If only all the people who complain about the M25 being a car park would use alternatives routes, I'd be able to get to work much quicker!
Regards
Technological inflation ? (Score:4)
Whenever a system is well done and integrated an application developper should only focus on features more than these disguised OS patches.
For example, on RiscOS [riscos.com], JPEG decompression is handled by the system and performed during the display refresh so that the memory needs are even lower. Most system routines are stored in software modules that can be accessed from whichever program, even BASIC script.
Concerning Mozilla, it is a shame that a Free Software Team is working on such a big thing instead of choosing to re-design it a more clever way.
BTW, here in Europe downloading dozens of Megabytes is a bit expensive, you know?
So, let's keep things small.
--
Re:So how well does it REALLY work now? (Score:1)
Clue for the day (Score:4)
alpha (the greek letter) is often used in equations to reflect a coefficient. In the case of calculating out the colour of a pixel, you may be left with an equation like :
a * alpha + b * beta
--------------------
c
In this particular case, "alpha" can be considered the coefficient for a source image intensity and "beta" can be considered the coefficient of a destination image intensity.
What this all boils down to is "alpha" transparency is the same as "beta" transparency, "gamma" transparency, or "horse" transparency. The use of the term "alpha" to describe it is worse than meaningless. Alpha can represent ANYTHING, that includes refractive quantities, air density, paint, or a splatter of your gran's homemade shoe polish.
It's called "transparency", not "alpha transparency". Perhaps semi-transparency, or if you're being really precise, "transparent filtering". Where in the latter case, you MAY use "alpha" to represent the filter.
HAND.
Is compression much of a factor anymore? (Score:1)
IMHO, with broadband becoming more prevelent in homes, the 72dpi web-standard is no longer being a benefit (by keeping the file sizes lower), but a drawback in clarity for sites that sell intricate products via images on their site or are graphic-oriented.
Is there any chance this may change in future browser versions?
Re:So how well does it REALLY work now? (Score:1)
PNG Support (Score:2)
CscHTML is available at: http://www.cscmail.net/cschtml
And if you are wondering what web-browser that is in the Screenshot, its the built in "minibrowser" in CSCMail 1.7.8 (using CscHTML as its HTML renderer)
Anyway, just wanted to let people know that there are other options out there.
-CZ
I see no M17 here (Score:2)
You are in a maze of twisty little daily builds, all different.
Re:Mozilla Vs. Netscape (Score:1)
Hmmm...
Re:M25 (Score:1)
Re:PNG & MNG Support? (Score:2)
The benefits of PNG, apart from the patent issues, are that you can do greater colour depths and the files are often much smaller than the corresponding GIFs.
In other words, I wouldn't even consider using GIFs any more.
MNG support is however almost non-existent outside M17.
Re:Clue for the day (Score:2)
The channel is called alpha (Red Green Blue Alpha) perhaps just by convention, but it's used very consitently.
- Isaac =)
Re:M25 (Score:1)
Re:Mozilla (will be) release(d) (Score:1)
Apparently, slashdot made the same mistake with M16.
Re:Clueless for the day (Score:1)
Great. Greg advocates PNG, documents it, generally makes the world a richer place, and you have to nitpick terminology. Maybe you have a (trivial) point, but your attitude is what I object to.
Geeks routinely abuse English, and a consensus develops that makes school teachers mad, but you'll find that the geek terms acquire a certain standardisation and add meaning to English it didn't have before.
For example, 3D graphics uses terms like "transparency" meaning [for 8 bit values] that (0 is opaque, 255 is clear), then introduces "opacity" to mean (0 is clear, 255 is opaque), THEN confuses us all by using translucency to mean (something between 0 and 255) - which goes against the dictionary - look it up.
English is a dynamic evolving thing, as are science and technology. Think about that.
Re:Clue for the day (Score:1)
Re:Mozilla (will be) release(d) (Score:1)
Using It Now (Score:1)
Try the nightlies (Score:1)
Just because it's not a Milestone release as it has been pointed out, there's no reason not to try a nightly build. They're getting more stable each day, and since some days ago a nice addition has been made: a "classic" skin.
It has the look and feel of Communicator 4, native widgets and such. (Can't tell if they're really native, or just a XPToolkit skin to mimic native widgets. Anyway, it looks good.) It even uses your system colors!!!
And more, Mozilla seems slicker, faster and more stable when using this skin... although it needs a little work still. So, check it out!
--
Marcelo Vanzin
Re:Clue for the day (Score:1)
Nik.
Re:When will the final version of Mozilla arrive? (Score:2)
Internet Explorer will give a friendly error page, but also the complete error message (yes, including the 404 at the bottom).
IE also lets you explore FTP sites completely as if they were part of your filesystem. Unlike Netscape, it'll display ALL information the FTP site sends you (including hello message) on the left frame in explorer.
Netscape is GOD DAMN SLOW.
1) Load up slashdot in netscape.
2) Resize the window.
3) Watch netscape start and stop trying to rerender the page
1) Load up slashdot in IE.
2) Resize the window.
3) Watch the smooth as silk dynamic resizing.
And that's only one small (but important) example.
Re:When will the final version of Mozilla arrive? (Score:1)
>regards,
And who cares?
Slashdot - a bad joke (Score:3)
Take this "announcement" for instance. A simple check around the Mozilla website would make it OBVIOUS that M17 is NOT out and won't be for a month or more.
Why is it then that Slashdot seems incapable of checking it's facts before announcing it's "scoop" to the world? Hilariously this is not the first time either - Slashdot announced M16 was out a good four weeks before it actually was.
Hmm (Score:2)
Re:You want the truth? (Score:4)
How about the test of "will I have to abandon this platform if a single company goes bust / decides to discontinue development"? Especially for businesses, this is important. It costs time to change the browser on 100 machines, and it costs a hell of a lot of time to answer the support queries of 100 users who've just been handed a new browser.
Opera and IE may be alright now, but they're not open-source so you may get left high and dry. That's a problem if you've just spent a fortune developing an intranet which relies on one of them.
Re:Clue for the day (Score:2)
So do you also object to using "pi" to represent a particular number close to 3.141592653589793238462643383279? Pi can represent ANYTHING, including products, probabilities, planes, the number of primes below a number, and my granny's phone number. It's not "pi", it's "the circumference of a circle divided by the diameter".
You can turn off the "Friendly HTTP error messages (Score:3)
Go Tools->Internet Options->Advanced, and then under the "Browsing" section there is a entry "Show Friendly HTTP error messages"
IE 5 shows them ("Friendly error messages") if there is a HTTP error code and the page size returned from the server is less than x bytes (where x is some number I can't remember now).
IMHO, it's quite a nice way to handle it - it tells newbies what has gone wrong and tells them ways in which they may be able to fix it, and yet it still enables website designers to display a custom web page (or redirect) on 404 errors, and advanced users can turn it off.
Re:png and quicktime plugin (slightly off-topic) (Score:2)
Re:When will the final version of Mozilla arrive? (Score:2)
I disagree. It might be reasonable to describe IE as the best HTML renderer (depending on your point of view). But there's a big bug in IE whereby if its market share exceeds about 70%, it hands control of the HTML standard to a company who wants to pollute it. Then IE will rapidly become the only browser, and after a while it will even become crap as an HTML renderer (because no competition to beat). That's a pretty big bug IMHO.
6Meg isn't big (Score:2)
I'm in Australia, so I feel your download pain. 6 Meg (in the case of Mozilla) isn't big at all for a major piece of software, though.
Don't forget that the Mozilla designers were (from the start) working on cross platform compatibility, so they couldn't rely on non-standard system libraries like the JPEG decompression lib you refer to in RiscOS.
IE 5 for mac (Score:4)
It's doing pretty good with standards, and is small and light-weight (takes like 4mb of memory - 7 mb install without java)
Surprisingly enough it even trounced the win IE in more than one way, on a platform they don't control; What's even more surprising were the reports i heard later on that the mac IE development team was dissolved - who knows what the reasoning behind that was. (check out http://www.mozillazine.org/talkback.html?article=
(Making the mac a better browsing platform than windows?! what were they thinking
Re:Technological inflation ? (Score:2)
Is that greatly different from being handled by a shared library, libjpeg?
Isn't that the same as shared libraries? (which is how the image handling gets done in Mozilla)
Re:too little too late? IE = 86% (Score:3)
I really hope that's not the case across the entire Internet (and let's face it, sampling client browsers is unreliable, much worse than checking server OS type, for example). Otherwise we can soon kiss goodbye to HTML and hello to the undocumented MS-HTML standard, and stop expecting it to be possible to write a competing browser that will display web pages.
Re:Webster XL (Score:2)
Besides the page mentioned in Greg's article, there is a very nice diagnostic set of images by Nick Lamb: http://www.ecs.soton.ac.uk/~njl98r/png-test
Also, there's my page for testing gamma support at
http://pmt.sourceforge.net/gamma_test/ [sourceforge.net]
Re:You want the truth? (Score:2)
It's only processor intensive if you have the browser being rendered in XUL. For a portable version, fast native widgets would be much better. The core rendering engine fits on a floppy, so rumour has it.
Download the nightly builds... (Score:2)
I have submitted about 20 bugs and all but about 5 of them are fixed at this point. In the last week a javascript bug that kept many of my companies web pages from working was fixed and as of last night mozilla works with junkbuster again.
I still have a few bugs that I want to see fixed before I can get rid of netscape: Mozilla crashes with some animated gifs, doesn't let you find on a page that contains frames, and the nightly builds don't handle encryption.
It still may be a while, but it really is coming. I can see it.
Re:too little too late? IE = 86% (Score:2)
It's a shame that IEs predominance is almost certainly due to its Windows integration and 'default' status, and not to the fact that is is, basically, the best browser currently available (and not in extended beta). Konqueror looks pretty good, though...
Re: (Score:2)
Nightly Build had 4.x skin (Score:2)
Every once in a while it still likes to hiccup, but for the most part it's pretty good software, I just hope that they can be smart about it and have a minimal d/l package that only has the core browser in it, since I don't use a lot of the other stuff included (no, I DO NOT want to use AIM, or Net2Phone, or...). Of course I'm just bitching, but it would be nice
PNG is fine with IIS - just missconfiguration (Score:5)
This is FUD. PNG's working in IE as opposed to Netscape when served by IIS is probably caused by a miss-configured web-server. And don't tell me that Apache can't be miss-configured either.
We had load-balanced web-servers which seemed to be identically configured. They were running NT 4 Server and IIS 4. Trouble was, the PNGs wouldn't show up in Netscape half the time.
Using "telnet myhost 80", I finally discovered why. One of the servers was returning the wrong MIME type for the PNG images. One was correctly returning image/png in the response header, the other was returning something like application/x-octet-stream.
The fix involved adding the image/png MIME type for
A correctly configured IE client differentiates based on file extension. So it ignores the MIME type in the response header, correctly displaying the PNG. Netscape on the otherhand looks at the response header, and thus cannot display the PNG if IIS is incorrectly configured.
The discussion on how IE uses file extensions is another issue.
Re:So (Score:2)
You correctly deduced that I'm not a mozilla developer. But, as Bob Young says, would you buy a car with the hood welded shut? And how much do you know about car engines?
The point isn't that *I'm* going to save the day. The point is that if AOL were to yank mozilla then *somebody* would continue the development. Moreover, any big organisation could *pay* somebody to continue development. Wheras if IE or Opera get yanked / modified / "upgraded" to something you don't want, then nobody else can do anything.
The source code to mozilla is useful, even to someone who doesn't speak a word of C. Its very *existence* prevents you from being tied to the whim of a single company. Get the big picture here, please.
Re:too little too late? IE = 86% (Score:2)
Sorry, we apparently have different definitions of "documented". I wouldn't count it as documented if portions are missing here and there. The Windows API is another good example of this. See all the API calls which the WINE people haven't managed to reverse-engineer. It's no good if people can only make half-baked imitations of IE's rendering. The point about w3c HTML/CSS is that you can implement the spec *precisely*.
Jumping the gun again... (Score:2)
Re:6Meg isn't big (Score:2)
Yeah, it's a shame. I hear people mention this all the time about Mozilla, and it has some merit.
I just wish they'd release the source code [mozilla.org] so someone, somewhere, could do something about it. Wouldn't that be nice?
Re:Clue for the day (Score:2)
Yes, a variable can represent anything, but we scientists/engineers use conventions to not get confused. Theta is an angle. Delta is a change. In images, gamma is a saturation and the alpha channel is a global effect on an image format. Yes it can be called something else, or refer to something else, but isn't it nice when people know what the hell you are reffering to? In my own words, fwip klupe neeet bwlithe nyak. No idea what I said, eh? Aren't conventions nice? To be "really precise" call it alpha transparency. That way people not living in your personal world know what the hell you are talking about.
Transparent filtering is a verb and not a noun anyway. They aren't interchangeable.
Java (Score:4)
Re:M25 (Score:4)
Re:PNG is fine with IIS - just missconfiguration (Score:2)
This is FUD. PNG's working in IE as opposed to
Netscape when served by IIS is probably caused
by a miss-configured web-server. And don't tell
me that Apache can't be miss-configured either.
Like the article said, it's due to a Netscape bug. Specifically, it was due to a missing comma in Netscape's "accept" header, which caused IIS to refuse to serve PNGs. What Netscape sent, up to version 4.51, was
Accept: image/gif, image/x-bitmap, image/jpeg, image/pjpeg image/png
I don't know why (or if) apache wasn't affected by the bug, but perhaps apache was accepting whitespace as a separator when it interpreted the accept header.
I suppose it would also refuse to send image/pjpeg, which was also combined into the single "image/pjpeg image/png" acceptable item.
Re:IE 5 for mac (Score:2)
That's why it's so good - Microsoft knows that if they want to compete on the Mac, they have to make a good product, because nobody will use their browser unless it's actually good. With Windows, they don't have to try so hard, because they know everyone will use it anyway.
What's even more surprising were the reports i heard later on that the mac IE development team was dissolved - who knows what the reasoning behind that was.
I'd heard that too, but a more recent rumor [appleinsider.com] would seem to suggest otherwise. Who knows.
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Re:IE 5 for mac (Score:2)
I really don't know for sure, but I'd imagine that Microsoft's mac teams probably have some people on them that were microsoft hating mac fans who went to work for microsoft just because it's a good job to have.
Still, if Microsoft screws up the Mac version of Halo, then the whole company, including the IE team can go straight to hell ;)
Re:IE 5 for mac (Score:2)
Apparently they've just been reassigned to overhaul the web browser for WebTV. Supposedly this was the plan all along, which makes sense considering they can reasonably leave the Mac version alone for a while.
Of course, I'd much rather they'd been reassigned to the Win/Unix IE ports, which could use their help (especially the later, of course). Amazingly, not only is Mac IE 5 cleaner looking and much more standards-compliant than any other browser, it also renders pages noticably faster than even IE 5 for Windows (based on my observations).
On the other hand, hell if I could spend all day browsing the web with a one-button mouse...
Re:PNG is fine with IIS - just missconfiguration (Score:2)
This is crap. All web clients should look at MIME type first and then file extension (if any). This allows perl scripts to dynamically generate GIFs and the like without having to change their file extension. Believe me, the biggest headache is having to program web pages for browsers that don't recognize MIME types correctly.
Re: (Score:2)
Re:You can turn off the "Friendly HTTP error messa (Score:2)
Re:Java (Score:2)
Re:Clue for the day (Score:5)
And it has been used that way for something like twenty years, ever since Ed Catmull (king geek of Pixar) coined the term to contrast with the then-prevalent "z-buffer." He created a new rendering technique called the - cue drum-roll - a-buffer. Catmull added a channel to the frame buffer - the "alpha channel", so that there were now five channels in the rendering system - red, green, blue, depth (z), and transparency (alpha). In fact, he first used it more for "coverage" than transparency. The a-buffer renderer computed sub-pixel polygons and then used the alpha channel to store what percentage of the pixel was covered (i.e., how much light got through from a further pixel). This enabled his renderer to produce anti-aliased images at a phenomenal rate (especially when compared to an over-sampling ray-tracer, which was then the state of the art in anti-aliasing).
At the time, the renderer was called "Reyes" for "renders everything you've ever seen" (and of course, for Point Reyes, near Silicon Valley). Guess what it is called these days? (pregnant pause) RenderMan.
You can learn more about a-buffers and dig up references to the original literature (Catmull first published at SIGGRAPH) in "The White Book", aka, Foley, van Dam, Feiner, Hughes. [amazon.com]
Re:M25 (Score:2)
Re:Try the nightlies (Score:2)
BTW to switch to the classic skin download the latest nightly from mozilla.org and then go to Edit | Preferences | Appearance | Themes - select classic and click apply theme.
I think the classic theme should be made the default in future.
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Re:IE 5 for mac (Score:2)
Or, as opposed to Netscape on the Mac. I agree -- IE 5 on the Mac is really sweet. I'm still sticking with Netscape out of habit and because it's what I use at home in Linux, but I'm definitely making a sacrifice by doing that.
Meanwhile, MacOS Mozilla M16 is barely usable. I tried it out, reported all the bugs I could find (lots of Mac-specific ones) and went back to Netscape. It's a pity -- Mac users are certainly a group that's receptive to using a non-Microsoft product but they'll never accept such a clunky UI.
Support my favorite Bugzilla report [mozilla.org]!
Re:Mozilla Vs. Netscape (Score:2)
web-interface to hardware (Score:2)
> www browser at them
What's wrong with you? That's a _GREAT_ way to do it! Because you know what, when you look at that 'install disk' the company sends along with said router, it's a good bet the install program will be multiplatform - Windows 98 and NT. Maybe Windows 2000 if you're lucky. It's a lot easier for the company who makes said router to put a web interface on the beast than worry about an install program for Windows 98, Win NT, Win 2000, Linux, FreeBSD, NetBSD, OpenBSD, OS/2, and whatever else is out there. Everybody's got a web browser these days. The only 'trick' to it is making the web pages coming out of the box be VERY standards-compliant (OLD standards, at that!).
what about the javascript? (Score:2)
send flames > /dev/null
mozilla.org says M17 "on the wire" 6/27/00 (Score:3)
The milestone plan is maintained here [mozilla.org]
If you look at it, you'll see that they have filled in the "on the wire" box, which appears to be an "actual" not a "schedule", because it's only filled in for past milestones and the dates appear (at first glance) to match the actual release dates.
If mozilla doesn't want people to shoot off "mozilla M17 out today" then they need to keep this page accurate and current (or get rid of it).
On the other hand, the M17 open bug and engineering task list is here [mozilla.org].
It lists 1073 bugs and tasks. So is M17 coming out later today or is it going to be 6 weeks away? This gives me the impression that mozilla.org is confused and doesn't have it's shit together on the communication side.
Re: (Score:2)
Browser Only? (Score:2)
Re:So (Score:2)
Microsoft Word is a closed product. KOffice (presumably) isn't. Guess which one I, a writer, will use?
Bang on: the one that makes the best use of my time. And KOffice ain't it: it doesn't have all the features I need.
Open source just doesn't count for SFA in real-world use. Feature-set, ease-of-use and stability are more important. KOffice, Mozilla and, frankly, Linux all fail to satisfy *my* real-world needs.
More open-source/Linux rah-rah yes-men need to get a clue about what most people really need in a computer. Maybe then we'd see some significant movement toward satisfying those needs properly.
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Translucency != Semi-Transparency (Score:2)
Yes, but transparent objects may have color. Think of colored glass. Translucent objects allow light to pass through, but scatter it to a certain extent. Think of frosted glass, or a fogged-up windshield.
Translucency would be kind of a cool feature for an image format (blurring images beneath it). You could probably set up a "translucency channel" if you wanted in a non-standard PNG chunk--call it tlUc (check the PNG spec [w3.org] to see why the capitalization is all wonky). The only problems being support (although it would degrade gracefully if a viewer followed the spec strictly), and the fact that it would probably take a lot of processor time.
It would be especially cool in MNG.
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Zardoz has spoken!
+4 Insightful? How about another point of view.... (Score:2)
Secondly, who believes that if AOL fired all the Netscape developers (who outnumber Open-Source contributors [mozillazine.org]) there'd still be a Mozilla? Considering that several laudable open source projects have languished without corporate support including IBM's JFS [slashdot.org] and almost everything SGI has GPLed for Linux.
Finally from a PointyHairedBoss perspective which is more likely a.)MSFT goes out of business or quits developing IE or b.) AOL decides to stop flogging a dead horse and concedes defeat by keeping IE as its default browser instead of spending money developing a second stringer to IE?
This is not a troll but a genuine counter-opinion, being Open Source does not mean diddly to most PHBs unless there is still someone to point at Apache has the Apache Group while Linux has Red Hat, SuSe, etc...Mozilla has AOL. Almost four years later, it is still primarily a Netscape operation with a minority of Open Source developers. Your argument would not hold sway with most bosses (heck, it didn't hold sway with my project manager and he's a developer) since it is unlikely that they are either a.) going to say "yeah, we can carry on development if it ever gets scrapped by AOL" or b.)We'll trust our entire corporate decision making on the hope that a bunch of random hackers will work on this software in their spare time.
Re:6Meg isn't big (Score:2)
which is the same as
2 1/2 paragraphhs = 1 side of a sheet of paper (about)
and about 250 words per paragraph
so that's 625 words per page
so mozilla will fit the same amount of information as 10066 pages of information
that is *way* to big
if the OS provides all kinds of libraries, then it doesn't make sense to redo all of that code for GUIs, Pngs, etc.
all for ease of development I suppose
(note: this isn't very informed about Mozillaso it really shouldn't be here, but the numbers I hope are somewhat interesting)
Author's comments/corrections (Score:3)
M17 schedule: I checked the Mozilla milestones page [mozilla.org] on Sunday before beginning the article and again Monday morning (3am PDT) just before submitting it; it claimed M17 would branch yesterday (26 June) and be on the wire today, and in fact it still says that--although there's now a red comment at the top (dated 27 May 1999!) that M17 won't be out for another couple of weeks. As a side note, I submitted the article with the following comment:
Unfortunately, it seems that both Jamie and I believed the other person was more informed about the true release date than we actually were. I apologize for the screwup.
Background: Back in April, around the time of the M15 posting, I commented to Jamie about the recent progress in PNG alpha support in browsers and the, shall we say, somewhat uneven accuracy of /. comments w.r.t. PNG and MNG features. He suggested I write something up for the next milestone, and I agreed to do that. Unfortunately, M16 showed up while I was on an extended business trip, so I wrote the article for M17 instead. I assumed it would be posted when M17 actually hit the wire, but it seems we were a bit premature. Oops...
Browsers and alpha support: As other comments have noted, OmniWeb and CscHTML also support full alpha blending, and Webster XL has not been abandoned--it's still under development. I've requested and/or have received screen shots for all three and will post them soon. On the other hand, I've been informed that Konqueror supports only binary (GIF-style) transparency, not full alpha blending. If anyone knows otherwise, please let me know. (I've downloaded a recent binary but am still missing a sufficiently recent libstdc++, I believe.)
Updated article: a corrected version of this article will be permanently available at http://www.libpng.org/pub/png/slas hpng-2000.html [libpng.org]. (The page is already there, but I haven't had time to update it yet.)
Hemos: I'm not Hemos, but I play one on TV.
Greg
Re:PNG & MNG Support? (Score:2)
Well, as the article says, PNG is used as an internal format for a lot of applications, including MS Office. One Macromedia app also uses it as its main format (can't remember which). There are also a lot of extentions having to do with scientific and geographical information, so I'd expect that those fields use it too.
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Zardoz has spoken!
Re:So (Score:2)
Your original post tried to coerce a closed-source user into admitting that open-source saves its users time and money, and that closed-source is just fundamentally wrong.
You ended with "can you at least see that some people like to save their own time and money?"
My point is, can't *YOU* see that for some people, using closed-source software *IS* saving them time and money?
There's room for and a need for both. Mindlessly bashing everyone who puts forward a closed-source solution or option is asinine. Open-source simply is not, at this time, a panacea.
And, frankly, if you're using a design process that doesn't focus on end-user needs, you should get the hell out of the industry.
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Re:LDAP (Score:2)
All my votes are spoken for, sorry. And I'm not familiar enough with how LDAP works to implement it.
But if anybody's interested, the bug report is here [mozilla.org]. You can also see the full list of LDAP-related bugs and feature requests here [mozilla.org]
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Zardoz has spoken!
Could IE be yanked? (Score:2)
I think there is a fair chance that Microsoft will choose to do something with their browser which buggers some customers. E.g. they may choose to change the APIs, then drop support for the ones you use in future versions. Then bring out web development tools which assume the latest version of their browser. This is just one scenario. They have been known to leave customers high and dry in the past. For instance, anyone who was relying on them maintaining NT on Alpha is now in a mess. I'm not saying it's impossible for AOL to try something similar, but if there's many people who are dissatisfied then somebody else will fork development. For instance, many people hate XULed components and consider it a waste of processing power. So there is a project around to release Gecko on GTK. If enough businesses wanted Gecko/GTK then they could get it released pretty fast. It's all about alternatives. With IE you're stuck relying on a single company who may not provide alternatives. With Mozilla, if
your business's needs are shared by other companies then something can be developed to address the need.
According to the article you cite, the balance has now tipped the other way.
Re:Yup... (Score:2)
Not many that were ever really big. Certainly, much less than the proportion of once-popular proprietory software which is now dead and unbuyable.
Re:Mozilla Vs. Netscape (Score:2)
Re:Mozilla Vs. Netscape (Score:2)
Just copy the nsswf-whatever.dll and the shockwave-whatever.class files to a directory called "plugins" under your mozilla-bin directory.