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2009.10.14 13:48 "Libtiff Tiff Tag TIFFTAG_STRIPBYTECOUNTS.", by Robert Zermeno

Everyone,
 
I hope someone can come up with a loop around for this.  So, I am trying to
programmatically open a Tiff file and read a segment of the image,
manipulate it, and spit it out into a new Tiff file.
 
My question is, my new Tiff file will have a size that is much smaller than
the original Tiff image.  I would like to define the TIFFTAG_STRIPBYTECOUNTS
count to the size of the new Tiff image height with its values being == to
Tiff image width.
 
My issues I experience is this.  Input Tiff image is of size 1001 x 901 and
Output Tiff image is say 300 x 300.  Now, when I perform the operation to
only select 300 x 300 pixels out of the 1001 x 901 pixels, the output Tiff
image STRIPBYTECOUNT count is == 901 with strip offsets always the value of
the new Image width - 100.  So, this case, the value is 200.  
 
This causes an issue because, I will not be able to see my photo I have
created programmatically.  Furthermore, you know that StripOffsets are
intertwined with StripByteCounts, so it too has a Count size of == 901 and
not 300.
 
Why did libtiff make it not possible for the user to do a
TIFFSetField(outTiff, TIFFTAG_STRIPBYTECOUNTS, ArrayByteCounts) or the same
for TIFFTAG_STRIPOFFSETS as well?  
 
It would be useful to override libtiff computation of these tags for user
specifics.  Does anyone know of a loop around to set these fields or maybe
have a possible solution to my issue?  If you must see my code, I can supply
it a little later on in the day.
 
Thanks to whomever that can enlighten me on this matter,
 
Robert