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possible bug -auto-orient IM 6.8.8.4 Q16 Mac OSX

Posted: 2014-02-08T15:19:08-07:00
by fmw42
I have the following image that contains exif:Orientation: 8 However, my attempts to use -auto-orient all fail on this an other similar images. The exif data is changed to orientation:1 but the image is not rotated.

http://www.fmwconcepts.com/misc_tests/a ... 100152.JPG

The command I have tried is

Code: Select all

convert SH100152.JPG -auto-orient tmp.jpg
Do I misunderstand -auto-orient or does this file have its exif data improperly represented in some way.

Can someone else verify?

Re: possible bug -auto-orient IM 6.8.8.4 Q16 Mac OSX

Posted: 2014-02-08T17:20:18-07:00
by magick
Your image has a left-bottom orientation. Try gimp. When it asks you to automatically rotate it returns the same image orientation as ImageMagick suggesting ImageMagick is likely working properly.

Re: possible bug -auto-orient IM 6.8.8.4 Q16 Mac OSX

Posted: 2014-02-08T17:57:53-07:00
by fmw42
GIMP does what you say. But when it says it has the correct orientation, it has already been properly rotated to portrait mode and when I save the file, other viewers present it correctly in portrait mode.

IM displays it correctly, but when saved, it still views improperly in landscape mode with left side down by many viewers.

If I view the image with IM display or GIMP, it seems to be rotated to the correct (portrait) orientation because I assume they read the EXIF orientation and correct for viewing. But several other viewers (Preview, GraphicConverter, Photoshop) show the image left side down (landscape). I assume they are ignoring the EXIF orientation.

I thought the whole point of -auto-orient was to rotated the image (data) appropriately and then set the EXIF orientation to 1 (so that it would have the correct portrait orientation). Am I misunderstanding what -auto-orient is suppose to do.

Re: possible bug -auto-orient IM 6.8.8.4 Q16 Mac OSX

Posted: 2014-02-08T18:09:59-07:00
by glennrp
fmw42 wrote:Can someone else verify?
Yes, I observe the same behavior with 6.8.8-4 on Ubuntu 13:10. Also, neither the latest Firefox nor Chrome rotates the image.

Re: possible bug -auto-orient IM 6.8.8.4 Q16 Mac OSX

Posted: 2014-02-08T18:11:21-07:00
by fmw42
thanks glenn

Re: possible bug -auto-orient IM 6.8.8.4 Q16 Mac OSX

Posted: 2014-02-08T18:16:42-07:00
by magick
  • -> convert SH100152.JPG -auto-orient test.jpg

    -> identify -verbose SH100152.JPG | grep -i orient
    Orientation: LeftBottom
    exif:Orientation: 8

    -> identify -verbose test.jpg | grep -i orient
    Orientation: TopLeft
    exif:Orientation: 1
Do you want the orientation to remain @ LeftBottom after its oriented? Here we rotate the image and update the EXIF orientation to TopLeft.

Re: possible bug -auto-orient IM 6.8.8.4 Q16 Mac OSX

Posted: 2014-02-08T18:18:31-07:00
by fmw42
Yes the result shows the correct EXIF data, but the image is not rotated. Should one not be able to do -strip afterwards and still see the image properly in portrait mode in any viewer, even GIMP?