AWARE SYSTEMS
TIFF and LibTiff Mail List Archive

Thread

2008.09.23 23:34 "[Tiff] TIFF Image Quality Question", by Rick Cone, Secure Payment Systems
2008.09.24 00:11 "Re: [Tiff] TIFF Image Quality Question", by Bob Friesenhahn
2008.10.01 23:18 "Re: [Tiff] Image Orientation tag and rotating images", by Richard Nolde
2008.10.01 03:03 "[Tiff] Image Orientation tag and rotating images", by Richard Nolde
2008.10.01 12:38 "Re: [Tiff] Image Orientation tag and rotating images", by Dr. Michael J. Chudobiak
2008.10.01 14:25 "Re: [Tiff] Image Orientation tag and rotating images", by Richard Nolde
2008.10.01 16:32 "Re: [Tiff] Image Orientation tag and rotating images", by Richard Nolde
2008.10.01 18:59 "Re: [Tiff] Image Orientation tag and rotating images", by Dr. Michael J. Chudobiak
2008.10.02 05:43 "Re: [Tiff] Image Orientation tag and rotating images", by Andrey Kiselev
2008.10.01 15:08 "Re: [Tiff] Image Orientation tag and rotating images", by Bob Friesenhahn
2008.10.01 16:02 "Re: [Tiff] Image Orientation tag and rotating images", by Edward Lam
2008.10.02 02:42 "Re: [Tiff] Image Orientation tag and rotating images", by Bob Friesenhahn
2008.09.24 01:14 "Re: [Tiff] TIFF Image Quality Question", by Phillip Crews

2008.10.01 15:08 "Re: [Tiff] Image Orientation tag and rotating images", by Bob Friesenhahn

On Tue, 30 Sep 2008, Richard Nolde wrote:

Concerning rotating images in tiffcrop:

> I've been working on the orientation tag issue for images rotated with > tiffcrop and I get two distinctly different results with a variety of

> viewers. Below are the outputs from tiffinfo on the original image and three

It seems like hardly any software supports the orientation tag correctly. It seems that perhaps Photoshop does things correctly.

A problem with updating the orientation tag is that often it is wrong. Perhaps the user wants to ignore the existing orientation flag, rotate the image, and then set the orientation flag correctly. Or perhaps the user wants to turn the image right side up and remove the orientation tag.

Ultimately, only the user knows for sure how to treat the orientation tag since they can see the image

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