AWARE SYSTEMS
TIFF and LibTiff Mail List Archive

Thread

2002.10.24 01:47 "1:2 Compression ?", by Nicholas Humfrey
2002.10.24 02:17 "Re: 1:2 Compression ?", by Peter Skarpetis
2002.10.24 02:20 "Re: 1:2 Compression ?", by Nicholas Humfrey
2002.10.30 09:16 "AW: tiff-digest V1 #259", by Bommineni Bhaskar ICN EN HC SE 21

2002.10.24 02:17 "Re: 1:2 Compression ?", by Peter Skarpetis

You need to make the strip size larger, this will give you better runs ie use something like

     TIFFSetField(tiff, TIFFTAG_ROWSPERSTRIP, (int)height); /* To achieve better
compression */

--
Peter Skarpetis
Serendipity Software Pty Ltd
67 Fitzroy Street
Surry Hills NSW 2010
Sydney Australia

Phone: +612 93321788
Fax:   +612 93321766
email: peters@serendipity-software.com.au
WWW:   http://www.riponce.com

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...