JPEG XR has features that appeal to advanced amateur photographers who use raw today and whom Adobe is courting for Digital Negative.
Microsoft announced some significant progress Tuesday in getting its HD Photo technology standardized as JPEG XR, a significant development for photographers like me who don't like the idea that their camera is discarding data when it converts image sensor information into a JPEG.
But the arrival of a higher-quality alternative to conventional JPEG could mean a bit of a turf war between Microsoft and Adobe Systems, which is trying to popularize a file format called Digital Negative (DNG). DNG is, in part, an attempt to bring some order to the chaos of proprietary "raw" image formats that higher-end cameras produce, giving photographers access to sensor data that hasn't been boiled down into a JPEG.
Microsoft positions JPEG XR chiefly as a higher-end replacement for JPEG, but in talking to Robert Rossi, Microsoft's principal program manager for emerging image and video technology, his opinions about JPEG XR's relation to raw and DNG jumped out at me.
Adobe's vision for DNG is that increasingly sophisticated software will take the hassle out of processing raw images, enabling DNG technology to spread more broadly. But Microsoft seems to believe JPEG XR will handle the needs of enthusiasts demanding more quality.
With JPEG XR, "You're giving people much of the capability of raw in a convenient file format. On the ultra-high-end there might be still a preference to use raw," Rossi said.
DNG has "a far more limited market or focus," Rossi added. "We are kind of approaching the raw/DNG functionality, but we would go much lower into the prosumer and consumer market, all the way down to cell phones."
Ed Lee, an analyst with InfoTrends, sees some competition between DNG and JPEG XR. "I think some of it comes around to who does the better job marketing the format and getting it adopted," he said.
Personally, I'd welcome a little competition among powerful companies trying to improve image quality, as long as the world isn't saddled with two competing standards that do the same thing. But although there's definitely some overlap, I suspect the two formats will remain more in separate domains--and not just because Adobe spoke positively about JPEG XR earlier this year, indicating it doesn't feel too threatened by JPEG XR.
If it fills Microsoft's expectations, JPEG XR will be used in a much larger, mainstream photography market. DNG and raw, in comparison, appeal chiefly to professionals and advanced amateurs today, and no matter how easy processing those images may become once downloaded from a camera, any amount of processing will rule out a large population.
JPEG XR does address one advantage of raw and DNG, the ability to preserve more of the original data from image sensors. JPEG retains 8 bits of data for the blue, red and green in each pixel, but cameras typically record 12 bits, with Canon's new 1D Mark III recording 14 bits and higher-end models 16 bits.
JPEG XR, though, has immense bit depth--with 16 or 32 bits of data recorded for each pixel's color, that means somewhere between 65,536 and 4,294,967,296 shades of tonal variation between black and white. Thus the "XR," or extended range, moniker. Regular 8-bit JPEG has 256 shades, which is plenty if they happen to be distributed perfectly, but not enough if you want to use photo-editing software to brighten up a face that's lost in shadow.
However, DNG and raw formats offer something JPEG XR can't: unprocessed data. Creating a JPEG XR image means the camera is making its best guess about color balance--compensating for the bluish hue of fluorescent lights or the orange cast of incandescent, for example--as well as reducing noise and sharpening edges. For those who want that level of control, stick with raw or DNG.