A clearer picture?
Microsoft gets generous with new photo format
By John “jaQ” Andrews firstname.lastname@example.org
Film photography enthusiasts might soon lose another plank in their platform against digital cameras.
For years, digital photos have come in pretty much one format: the JPEG, named for the standards body that certified it, the Joint Photographic Experts Group. Most digital cameras save pictures in the JPEG format, making it ridiculously simple to copy, edit and share the photos you take with anyone. Very convenient, but image quality has never been up to film’s standards, with color reproduction suffering and pixelation creeping into pictures.
More advanced cameras can output what’s called a “raw” file, which more faithfully preserves images but needs to be processed before it can be viewed by anything other than a photo editing program. Professional and serious amateur photographers sometimes prefer this format, especially if their final product is prints rather than digital images. But it’s just not as simple to work with and share as JPEG, requiring much larger file sizes and specialized software.
Shooting for something that takes the best aspects of each format is a new proposed standard called JPEG XR, for the “extended range” of color tones that can be displayed. Vista users have already seen the format in the form of Microsoft’s HD Photo. In fact, Microsoft wants HD Photo to become the JPEG XR, free for all the world to use. Nice of them, huh?
JPEG XR’s main selling point is that it holds more information than traditional JPEG. Each pixel in a JPEG image is made up of 8 bits of data. Raw files, which include everything a camera’s image sensor records, typically have 12 bits per pixel. JPEG XR will hold 16 or 32.
While that might sound like a recipe for ballooning file size, Microsoft claims a JPEG XR file can be about half the size of an equivalent JPEG file. That’ll come in real handy for photos of very high resolution, and JPEG XR supports some very high resolution. Today’s 12 megapixel cameras might output images that measure 4,000 pixels wide by 3,000 pixels high. JPEG XR supports images as large as 68.6 terapixels, or 262 million pixels square.
How exactly the new standard will take its place in the computing world isn’t yet clear. It won’t simply replace JPEG, because older operating systems and software programs won’t be able to read it without updates or patches. A similar update to the standard, JPEG 2000, never really took off simply because plain old JPEGs were so entrenched and plenty good enough for the vast majority of people.
Many analysts believe JPEG XR’s niche, at least initially, will be among digital photographers who want the color depth and clarity of raw images without the manual processing they require. By storing their images in JPEG XR format, they’ll not only save storage space, they’ll have pristine versions of their photos in a standard that should slowly take greater hold. In a few years, Web browsers and other applications will support the new format natively, and only a few holdouts still running ancient operating systems won’t be able to view it.
For now, the new standard is still a proposal, so keep using those ordinary JPEG files. Or 35mm film. Whatever.