Caps for CIE 1931 XYZ color space for HDR processing

[Josh Doe]

I'm interested in processing HDR images, and a new library libhdr
(derived from pfstools) has just started, in order to provide HDR
processing including tone mapping. They use the XYZ color space (CIE
1931), so I'd like to define caps for this. I'm not sure if there's
interest in this colorspace, but perhaps I could at least get some
feedback on this.

video/x-raw-xyz
width = (int) [1, 2147483647]
height = (int) [1, 2147483647]
endianness = (int) BIG_ENDIAN, LITTLE_ENDIAN
depth = (int) 16, 32, 64, 128
luminance = (string) "relative", "absolute", "display"
channel_order = (string) "XYZ", "XYZA", "ZYX", "Y", "YA", ...

Here's the PFS file format spec:
http://www.mpi-inf.mpg.de/resources/pfstools/pfs_format_spec.pdf

Thanks,
-Josh