JPEG XR

|

New
Photoshop plugin
brings HD Photo
to Mac OS
When JPEG2000 came out, I read about it and got the plugins for Photoshop, but ended up never really using them. There was no support in browsers, and few people cared about the added capabilities to include text and metadata. PNG was becoming the new standard to follow for web images.

Then last July the Joint Photographic Experts Group (the JPEG standard writers and maintainers...) had a press release called JPEG 2000 Digital Cinema Successes and Proposed Standardization of JPEG XR In it they discussed the- what turns out being limited- success of the JPEG2000 standard. Improved quality, Photoshop and browser plugins aside, the thing never caught on and looks like it'll die in all venues save one- motion: JPEG2000 was extended to include digital cinema and for that it's catching on. JPEG2000 for images will more than likely be canned in favor of JPEG XR (extended range). The proposed new standard is designed for upcoming digital cameras, is based on technology introduced by Microsoft in its Windows Media Format and is currently known as HD Photo. Windows Vista supports it.

I'm posting about it here because the news release mentioned that there would be discussion of the new standard at the group's meeting in Japan on November 12-16. That meeting is taking place now, and the Microsoft HD Photo format has become a new standard called JPEG XR.

And with the new standard, there's a Photoshop plugin available for Mac OS. That's new. The version for Windows has been around for a while since Vista supports the format natively. But browsers don't. And the plugin creates HD Photo Beta format (.wdp) images, not JPEG XR.

The results of using the plugin in Photoshop CS3 on a Mac aren't earth shaking. The option isn't available in the "Save for Web" dialog (which makes sense since the web has no use for HD Photo yet...) but in the standard "Save" dialog, you can choose HD Photo. You get an initial dialog that lets you select a level of compression similar to JPEG. There's an "Advanced Settings" option available that I'll need to explore before I can do anything with it beyond making a screen capture. I opened a RAW file, cropped it to a small size and tried saving it several ways. As a "60" quality JPEG from the "Save for Web" dialog I got a 28,587 byte file with no color profile or gamma embedded. As a "6" quality JPEG from Photoshop's "Save" dialog I got a 49,911 byte file that's bigger because of an attached color profile. Finally, saved as an HD Photo (.wdp) from the standard "Save" dialog I got a 44,298 byte file that looks very much like the JPEG with a profile, though I can't see it in a browser. The file size is a bit smaller, and on close inspection, the JPEG fragment "squares" are much smaller and more diffuse. Blocks of tone are smoother.

One more thing: along with the new standard is a new color space. It's called ScRGB, it's been built in to Windows Vista, and it extends the sRGB standard. You can read about the new standard in a PDF from the International Electrotechnical Commission. c/net has a good ScRGB article, too. It looks like the extended space, more color than the eye can see, will be part of our design futures.

You can download the three test files in a zip archive and look at them yourself.

A brief addition: I saved the original Photoshop file as a lossless PNG and a lossless WDP. I dragged each onto the original as separate layers, and zooming in to 3200% I could see no differences among the three. The PNG is 307,664 bytes while the WDP is 290,548 bytes. That's almost 17K. Hopefully, Adobe and Apple will see that resistance is futile.

Also of note: The lossless version of the HD Photo format supports Alpha channels, but not transparency. That means any transparent pixels will be filled in with default white when the file is re-examined. PNG actually supports 8-bit transparency.

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