Forum Moderators: not2easy
Microsoft photo standard comes into focus [news.com.com]Microsoft's alternative to the ubiquitous JPEG image format could soon become a standard, a major step in the company's ambitions to spread the technology and boost its Vista operating system.
In coming months, 16 national standards groups will formally vote on whether the Joint Photographic Experts Group, after which the JPEG file format is named, should make Microsoft's relatively new HD Photo format a standard. Getting to this stage is a good sign in Microsoft's view, and the company has hopes the format will be accepted as a standard called JPEG XR by mid-2008, said Robert Rossi, principal program manager at Microsoft for emerging image and video technology.
Before all of the Microsoft haters jump out of the woodwork consider this: The JPEG format is a "lossy" image format that actually degrades picture quality each time your files are edited. Microsoft's newly proposed HD Photo uses lossless compression that retains the full quality of your images after editing and resizing. In addition Microsoft says image sizes for HD Photo files are smaller than JPEGs.
If:
1) MS owns all the relevant patents (possible, but but guaranteed, and impossible to know), and
2) MS is willing to allow unrestricted royalty free use (so, for example, Firefox and Safari can use it). They say "royalty free", but are there any non-moentary requirements?
Then I have no problem with using it.
How does it compare with lossless JPEG, JPEG 2000, other formats etc?
This comparison was done last year and posted on a video website I'm a member of. Overall the Windows format does produce a slightly smaller file than JPEG2000 and also appears to produce a slightly better image in some cases but not all images. Unless they have improved it since this test was run its hardly a breakthrough in compression technology.
Remember when PNG was supposed to supplant GIF?
Remember when JPEG2000 was supposed to supplant JPEG?
I think the question asked earlier, "What's JPEG2000?" says it all...
I hope it works out, but I'm not holding my breath...
Remember when PNG was supposed to supplant GIF?
If the alpha channel in .PNG had been natively supported by IE6 I'd bet that both .JPG and .GIF would have been distant memories by now. At the very least .GIF would have been. Being able to use a single graphic with transparency that will blend with any background has tremendous advantages as I'm sure you are aware.
As far as the Windows photo format becoming popular unless it gets wide browser support fast I'd predict .PNG will most likely be the choice format for images shortly now that IE7 does support alpha channel in .PNG I know once IE6 fades away enough that is what I'll be using.
My guess is it will be used more for archiving and digital cameras if it's used.
I can already do lossless rotation of jpegs, but lossless resizing? By very definition resizing is a lossy process.
Anyway, ideally, saving an image into jpeg should be your last step (and sharpening, your second to last step, right?) and should only happen once or twice in the life of an image.
I think the real news is actually the XR part. If it's true that it has excellent lossless compression and it also can handle color depth of 16 bits (or 32 but even Photoshop CS3 on a 64-bit machine can't really handle 32-bit color yet) that gives it advantages over both jpeg (8 bits, lossy) and RAW (12 bits, no compression). Even if the compression were 20% worse than jpeg, I could certainly see it in high-end cameras before too long. It almost sounds more like a RAW killer than a JPEG killer.
Any camera nuts know what RAW has that JPEG-XR doesn't?
Or are they using HD as a buzzword?
Hmmm, let's see... The local eye clinic is now offering "High Definition (HD) Laser" treatments, the girlfriend recently came home speaking of her girlfriend's HD sunglasses, my site is HD (best viewed at 1600 x 900)...
Bzzzzz.... :)
Microsoft's newly proposed HD Photo uses lossless compression that retains the full quality of your images after editing and resizing. In addition Microsoft says image sizes for HD Photo files are smaller than JPEGs.
That's impossible - and wrong.
HD Photo supports BOTH lossy and lossless compression.
A couple of key points from the Wikipedia article on HD Photo:
Because all encoding phases except quantization are lossless, HD Photo is lossless when all quantization coefficients are equal to 1. This is not true of JPEG. JPEG defines a separate lossless mode which does not use the DCT, but it is not implemented by libjpeg and therefore not widely supported.
The HD Photo bitstream specification claims that "HD Photo offers image quality comparable to JPEG-2000 with computational and memory performance more closely comparable to JPEG", that it "delivers a lossy compressed image of better perceptive quality than JPEG at less than half the file size", and that "lossless compressed images ... are typically 2.5 times smaller than the original uncompressed data".
HD Photo improves on the techniques used in JPEG, but is very similar in concept.
JPEG2000 is a different animal, based on an entirely different compression technique - wavelet compression.
For the viewer, the difference between JPEG and JPEG2000 can best be seen in highly-compressed images. A highly-compressed JPEG image will exhibit "the jaggies" and color fringes. A highly-compressed JPEG2000 image will appear blurred.
I prefer the latter.
A few years ago, there was some concern about MPEG video (which is based on JPEG compression) causing headaches during long viewing periods. Haven't seen anything about that lately. One of the supposed advantages of wavelet compression is that viewing wavelet-compressed video doesn't cause this fatigue.
8-bit PNG is worthless. You're better off using GIF.
Anybody remember this old dog [i3a.org]?
but then you look at the sample images, with the large visible blocks and wonder "In what way is this actually lossless?
If you are referring to that PDF I linked to all of those samples are not using lossless compression so artifacts are to be expected. One interesting thing to note according to the tests JPEG2000 outperforms the windows format when really high compression is used. As suggested it would be suitable for cameras. As far as getting the information back I'd find that highly unlikely because if that was possible it would just use that information for display.
Be interesting to see some comparisons in file sizes at lossless compression compared to JPEG2000. If the lossy samples are any indication it won't be much.
if that was possible it would just use that information for display.
That's what I was driving at. I didn't read carefully enough to see that JPEG XR had a lossy compression too. Also didn't realize that JPEG had a lossless version that simply wasn't supported by libjpeg. All very interesting.
The term HD comes from the fact that they support up to 32-bit floating point or integer images (jpg only supports 8-bit and tiff is either 8 or 16 bit). This means you can store hdr images (much like in the hdr radiance format).
Again I am not quite sure about the usefulness.
In Photography I always use RAW (full resolution, no whitebalance, sharpening, color applied yet) and for viewing JPG is more then you need (displays and printers don't support the high color ranges).
I'd have agreed if you'd said 24-bit PNG but for relatively simple graphics an 8-bit PNG file is about 20% smaller than the equivalent GIF file and with dither it's possible to shrink quite complex large dimensioned graphics to acceptable file sizes.
"8-bit PNG is worthless. You're better off using GIF."I'd have agreed if you'd said 24-bit PNG but for relatively simple graphics an 8-bit PNG file is about 20% smaller than the equivalent GIF file and with dither it's possible to shrink quite complex large dimensioned graphics to acceptable file sizes.
Fair enough. However, I don't see many places where that size reduction actually merits having to implement the Microsoft Funky Filter (and subsequent non-caching of images). The xparency mask is binary, just like GIF, but isn't honored by MSIE.
I NEVER use dither in GIF. It increases file size.
