2005.03.22 17:20 "[Tiff] tif_jpeg.c and 12bit JPEG Files", by Frank
Warmerdam
Thread
2005.03.22 21:59 "Re: [Tiff] tif_jpeg.c and 12bit JPEG Files", by Bob Friesenhahn
I have modified the JPEGDecode in tif_jpeg.c to take care of repacking the 16bit data into 12bit packed format. BTW, the changes are now all committed in tif_jpeg.c in the CVS head for libtiff for use with the Mk1 libjpeg.
I just verified your updates against IJG JPEG 6b (not the Mk1 version) built at 12 bits and am happy to report that it almost works! I say *almost* since the image appears as if the red and green samples have been interchanged. Trees and grass in the image are shown as red.
Performance seemed slower than expected, but then again my test image is 125MB, tiled, and multi-frame encoded (7680x13824 largest frame) so that might explain the slowness.
Did you include a writer-path in your updates?
Bob
======================================
Bob Friesenhahn
bfriesen@simple.dallas.tx.us, http://www.simplesystems.org/users/bfriesen/
GraphicsMagick Maintainer, http://www.GraphicsMagick.org/