Page 1 of 1

-auto-orient is working incorrectly with thumbnails

Posted: 2010-05-03T06:13:46-07:00
by finrist
We have images (jpg) whose thumbnail in the EXIF has "Orientation: 6" but the actual image has not. But when we convert it with "-auto-orient" it rotates the image 90 degrees even though only the thumbnail is said to be rotated.

The image looks good in every program I've tested, GIMP, Photoshop, Windows own, Mac OS X own, etc.

Re: -auto-orient is working incorrectly with thumbnails

Posted: 2010-05-04T06:46:22-07:00
by finrist
More info:
Link to the image: http://jump.fm/KVSOU
Version: ImageMagick 6.4.9-7 2009-03-03 Q16 OpenMP http://www.imagemagick.org

Re: -auto-orient is working incorrectly with thumbnails

Posted: 2010-05-04T18:55:58-07:00
by anthony
-thumbnail will strip the profile containing photo orientation image that -auto-orient needs. -auto-orient can not work when it does not have information to work with!

You MUST apply -auto-orient BEFORE -thumbnail.

Alternative use -resize, then -auto-orient, then -strip

Re: -auto-orient is working incorrectly with thumbnails

Posted: 2010-05-04T18:57:57-07:00
by anthony
If you mean the thumbnails within JPEG. They are not currently handled by IM. More typically they are removed with either -strip or -thumbnail as part of processing, or re-created after processing.

Re: -auto-orient is working incorrectly with thumbnails

Posted: 2010-05-04T23:59:36-07:00
by finrist
anthony wrote:If you mean the thumbnails within JPEG. They are not currently handled by IM. More typically they are removed with either -strip or -thumbnail as part of processing, or re-created after processing.
Yes, it is the thumbnail within the JPEG that is not working. This thumbnail has "Orientation: 6" attached to it, but when i use -auto-orient IM applies this orientation to the real image, not only the thumbnail.