2008.07.09 19:35 "Re: [Tiff] Problems with non-symmetric tiled images", by Bob Friesenhahn

I plan to create tiff files on the Mac OSX using libtiff (which by the way can be made into a universal 32/64 bit library quite easily).

The tile width is 128 and the length (height) 48. I can create the files using libtiff without error. They read in just fine in another program using libtiff. Also, Photoshop on the mac displays them just fine.

However, when I use any Apple's programs (Preview, Safari, etc) the images is all jumbled up (symmetric tiles look fine), so I entered a bug on their system. That said, I probably won't hear anything on this for ages.

What version of libtiff are you using? Different versions of libtiff have different bugs. Some bugs are dependent on endian-order with big-endian bugs being more common than little-endian due to the system developers used, and because little-endian hides certain types of bugs.

I recommend using libtiff tiff-3.9.0beta rather than 3.8.2 or older.

The, it occurred to me - it could be a problem with libtiff, and maybe Photoshop uses libtiff, so it could be that Apple's reader was properly designed. [Thinking that the use of non-symmetric tiles is probably not very common.]

You are correct that there are lots of readers which do not handle tiles. Perhaps this includes Apple's readers. Libtiff strives to implement the specification correctly and does as good a job as any other software.

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