2009.07.07 00:38 "[Tiff] tiffcrop using incorrect units", by Kevin Myers

I am attempting to use the tiffcrop utility to crop some extremely large images (multi-hundred megapixel) so that I can process the resulting smaller images in an OCR application. Unfortunately, tiffcrop seems to be ignoring or misinterpreting the pixel units that I have specified using the -U option. Here is the command that I used:

tiffcrop -i -E top -U px -X 2400 -Y 4800 oldfile.tif newfile.tif

I am using libtiff version 3.8.2 under Windows XP. Based on results with different -X and -Y values, it appears that tiffcrop is interpreting the values as inches rather than pixels.

Am I doing something wrong?

Thanks,
Kevin M.