2002.10.24 01:47 "1:2 Compression ?", by Nicholas Humfrey

Hi,

This is probably a stupid question but I have been hunting around for quite a while and can't solve it. Had a look at the header files and manual pages but no luck...

How do I enable basic 1:2 compression for a TIFF file - in addition to the Image codec compression - such as Packbits.

I have two identical image files - one compressed using a graphics program and one compressed using libtiff. When comparing using tiffcmp - they it finds no differences.

However the libtiff file is twice the size of the graphics editor. When I get information about the file I am told that although both files are compressed using PackBits another field says that the libtiff file is compressed 1:1 and the other file is compressed 1:2.

Is this an extension to TIFF that libtiff can't write? - I can read/decode the compressed files fine...

Cheers,

nick.