1999.09.16 10:21 "Re: uge G4 fax compressed TIFF", by Ivo Penzar
Our G4 implementation (non LibTIFF) had problems when the pixels per line value got over 65K. this was due to pervasive use of "shorts" in the G4 algorithm. There were actually two problems, one when the length of the line was over 65K, and one when a single run within a line was over 65K.
I am not sure from the description below which dimension is which, but if the 75K dimension is the number of pixels per line, LibTIFF may be running into the same problem that we had.
It is all about a few shorts to be prolonged to (unsigned) longs - turn your debugger on. With these tweaks we read without a problem 275K wide G4 images (scanline by scanline, of course).