2005.03.05 22:02 "[Tiff] TIFFDefaultStripSize funky", by Bob Friesenhahn

Compression ratios when using deflate compression are supposed to improve up to 32K of data (according to Adobe spec). Since TIFFDefaultStripSize uses a target of 8K of data per strip, I decided to estimate the number of rows for a 32K strip. This value was then passed to TIFFDefaultStripSize() as the suggested value. Rather than returning something close to my suggested value (36), TIFFDefaultStripSize() returned the same value (9) as it did when the strip_size argument is set to 0. This behavior seems wrong to me.

I am at a loss as to why this happens since the code in libtiff seems to be designed to return the user-provided value unless the compressor choses to use a different estimator than _TIFFDefaultStripSize.


Bob Friesenhahn
bfriesen@simple.dallas.tx.us, http://www.simplesystems.org/users/bfriesen/
GraphicsMagick Maintainer, http://www.GraphicsMagick.org/