2000.10.14 22:15 "tif_getimage.c and YCbCr", by Frank Warmerdam
Folks,
There seem to be some serious bugs in the YCbCr support in tif_getimage.c (the ReadRGBAImage code) for odd sized images. For instance it doesn't work properly for 4,4 sampled code unless the image width and height is a multiple of four (and strip or tiles sizes are also a multiple of four).
Before I spend alot of time trying to fix this I would ask:
- Is there anything in the specification that requires factorable sizes when using YCbCr images?
- Is there anyone else interested in fixing this problem? Ideally someone who cares more about YCbCr images than I, and who can do more testing than I might?
- Any other advice?
The bugs can be reproduced by converting an odd sized image to YCbCr form with "rgb2ycbcr -h 4 -v 4 -c none", and then trying to convert back to RGBA with tiff2rgba.
Best regards,
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I set the clouds in motion - turn up | Frank Warmerdam, warmerda@home.com
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and watch the world go round - Rush | Geospatial Programmer for Rent