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TIFF and LibTiff Mail List Archive

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2007.04.25 13:23 "[Tiff] orientations 5-8 not handled correctly", by Dr. Michael J. Chudobiak
2007.04.25 13:56 "Re: [Tiff] orientations 5-8 not handled correctly", by Frank Warmerdam

2007.04.25 13:23 "[Tiff] orientations 5-8 not handled correctly", by Dr. Michael J. Chudobiak

Hello all,

libtiff correctly flips images with orientation tag values of 1-4, but it does not handle orientations 5-8 correctly. 5-8 require rotations rather than horiz/vert mirroring (see http://sylvana.net/jpegcrop/exif_orientation.html).

Specifically, libtiff/tif_getimage.c: setorientation has code like:

         switch (img->orientation) {
                 case ORIENTATION_TOPLEFT:
                 case ORIENTATION_LEFTTOP:
                        bla bla bla....

The code treats ORIENTATION_TOPLEFT the same as ORIENTATION_LEFTTOP, but obviously they are not the same.

Is this deliberate?

This has come up in the gnome bugzilla, see http://bugzilla.gnome.org/show_bug.cgi?id=428725#c52.

We need to fix it either in the gnome tiff pixbuf loader, or in libtiff.

Suggestions?

- Mike