Among the interesting sessions I've been to at WinHEC was one on something I'd never heard of before: Microsoft's Windows Media Photo file format. It is, basically, a counterpart to Windows Media Audio and Windows Media Video for photo images. And Microsoft says it's dramatically better than JPEG, the current photo lingua franca, from a technical standpoint.

Judging from the demo this morning, that could be true. Windows Media Photo is designed to preserve more of a photo's information (such as dynamic range) than JPEG does, and to provide better-looking photos at a higher compression level. (Microsoft says that it'll still produce a reasonable-looking photo even at 25X compression.)

WMP also has various other technical advantages, such as allowing devices and software that support it to render a region of the image, or a lower-res version, without having to wrestle with the entire photo at full resolution. And it provides for both lossy and lossless compression with one algorithm.

In other words, it sounds kind of neat. But the session this morning examined it only from a technical standpoint, which is a reasonable take for a technical conference, but one which left me with lots of questions.

For Windows Media Photo to make sense, it needs to be supported by cameras, printers, photo software, browsers, and an array of other devices and applications that create, edit, manage, or simply display photos. Does Microsoft plan to invest immense amounts of energy in convincing a gazillion third parties to implement it? Does it see Windows Media Photo as replacing JPEG, or providing an alternative? (Right now, you'd be nuts to buy a camera which only captured images in WMP; one that provided it as an option might be intriguing.)

There are possible nightmare scenarios here, like WMP-format photos existing on the Web and browsers other than IE not being able to display them. How'd you like to have to worry about photo formats when browsing the Web?

WPM is wrapped up in Microsoft's XPS portable document/printing standard; devices that support XPS will apparently have to support WMP. That could help it gain traction. And Microsoft is pretty good at getting its formats out there when it's really interested and they've got meaningful advantages - neither Windows Media Audio nor Windows Media Video has killed off competitive formats, but they're both pretty pervasive (in products that don't have an Apple logo on them, at least).

Still, technical virtues are only one part of the file-format puzzle. JPEG2000 was supposed to replace JPEG. It seems to have some of the same virtues as WMP, in open-standard form. Yet it's gone exactly nowhere.

WMP support will be built into Vista, and Microsoft says it's planning to release some sort of add-on for Windows XP. More details as we get 'em...