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August 2008

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2008.08.27 19:32 "TIFFReadScanline doesn't work at all for subsampled YCbCr JPEG data", by Tom Lane

I'd be interested in getting comments on
http://bugzilla.maptools.org/show_bug.cgi?id=1936

Although TIFFReadScanline is documented not to work for fetching
subsampled data as such, it ought to work for data that's been
converted back to RGB, as tiff2ps requests libtiff to do.  The
problem basically is that too many decisions are made before the
	TIFFSetField(tif, TIFFTAG_JPEGCOLORMODE, JPEGCOLORMODE_RGB);
call and never revisited.  The check-ycbcr-subsampling kluge is
definitely making things worse, but it fails even without that.

Years ago I might've been able to fix this myself, but I no longer grok
libtiff well enough; can anyone help?

			regards, tom lane