14 Apr
2011
14 Apr
'11
12:58 p.m.
When I was looking for decoders, the Canon format was what they claimed
to b lossless jpg format, and it was close enough to use a jpeg library
to decode the payload. There was also a decoder which derived a 48 bit
image file by doing a debayer function.
The resulting 16 bit tiff (16 bits / color x 3 colors) causes most
copies of windows desktop to implode in horrible ways. Just landing on
the directory with the pictures would crash the desktop code. Linux was
not much better with it.
I needed to have a format if possible to carry the output from a 14 bit
camera, and even though it was 1 color, still the tiff code failed
horribly. The problem is actually in the tiff spec, and in some vendors
and libraries implementation of that format.
Jim
On 4/14/2011 12:44 PM, Eric Smith wrote:
Tony Duell wrote:
If that 'raw' format is documented, then
presumably it's possible to
write a lossless converter from that to a format that gimp can
handle. If
the rw format is not docuemtned, then that would be a very good reason
for me not to even consider that camera.
It is in general not possible to write a lossless format converter
from a camera "raw" format to any conventional image format. In raw
formats, the color primaries are not at coincident spatial locations
as they are in conventional image formats such as JPEG.
The raw formats also tend not to be publicly documented, but people
reverse engineer them to add support to open-source software, e.g. dcraw.
Eric