Better JPEG standard due in 2009
JPEG XR image format, created initially by Microsoft, passes a standardization milestone and should become a published standard this year.
image format created by Microsoft that promises a number of advantages over JPEG, has cleared a key standardization hurdle., an
The Joint Photographic Experts Group, which standardized the original and still ubiquitous JPEG format, sent JPEG XR to the "final phases of standardization" after a vote at a January meeting, the group said Thursday. That means the standard's future is more certain.
"The committee expects the JPEG XR International Standard to be published later this year," the group said.
JPEG XR offers a few advantages over JPEG, according to Microsoft. For one thing, as the XR "extended range" abbreviation suggests, it offers greater dynamic range--the span between the brightest brights and darkest darks in a photo.
JPEG uses 8-bit encoding that provides 256 gradations, but JPEG XR can use 16 bits or more for finer distinctions and more editing flexibility. Newer digital SLRs typically record 14 bits data, and the hobbyist practice of combining multiple shots into a single high-dynamic range image also benefits from more bit depth.
Another advantage of JPEG XR is that it uses a more efficient compression algorithm that provides either twice the image quality as JPEG at the same file size, or half the file size for the same quality, according to Microsoft. And unlike JPEG, setting JPEG XR to record at its highest quality level loses no information to compression artifacts.
Last, it's easy with JPEG XR to decode just a portion of an image, making it faster to zoom in on an image, and Microsoft designed the technology to work well baked into camera image processors' circuitry, not just to run in software.
Microsoft hopes JPEG XR will become widely used, but it faces a huge challenge in displacing conventional JPEG. It's taken the first steps, though: Windows Vista supports the format on which JPEG XR is based, called Windows Media Photo and later HD Photo. Microsoft also has released HD Photos support for Photoshop and
(Via Bill Crow)