2008.10.02 05:43 "Re: [Tiff] Image Orientation tag and rotating images", by Andrey Kiselev
On Wed, Oct 01, 2008 at 10:32:22AM -0600, Richard Nolde wrote:
My first question is whether I have made the correct adjustments to the orientation tag for rotations of 90, 180, and 270 degrees clockwise.
- libtiff support for orientation is a little odd, because libtiff automatically adjusts for orientations 1-4 (which preserve the height and width), but not 5-8 (which swap height and width). Beware!
What file are you referring to when you say that libtiff automatically adjusts for orientations 1- 4?
There is a TIFFReadRGBAImageOriented function which handles some of the orientation stuff, but unfortunately it doesn't cover all the possibilities. There was a bug filled in our old Bugzilla on the issue (which is now lost) and it wasn't fixed because I haven't a good idea how it should be done.
Andrey V. Kiselev