Legacy ImageMagick Discussions Archive

Hi,

I have a JPEG that has orientation data in it, but it doesn't seem to be stored in the image's Exif data. If I run the image through convert with -auto-orient, it rotates the image, and "identify -verbose" is also able to extract the orientation:

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identify -verbose 0000221676_0.jpg | grep Orientation
  Orientation: RightTop

but neither of these commands produces any output when run:

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identify -format '%[EXIF:Orientation]' 0000221676_0.jpg
identify -format '%[IPTC:2:131]' 0000221676_0.jpg

The image in question is available here: http://wootangent.net/~lsd/blah/0000221676_0.jpg

I'm doing this as part of the image upload flow in a website, so I'd like to avoid the cost of running "identify -verbose" if possible. Is there another way to get the orientation information from images like this?

I'm not sure what you are asking. exiftool reports:

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XMP-tiff:Orientation='Rotate 90 CW'

IM does not find any EXIF Orientation data in the file. Though it should from the string formats at http://www.imagemagick.org/script/escape.php.

You can that it does not find it by

identify -verbose 0000221676_0.jpg

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  Properties:
    date:create: 2013-07-17T20:09:08-07:00
    date:modify: 2013-07-17T20:09:08-07:00
    dc:format: image/jpeg
    exif:ApertureValue: 4281/1441
    exif:ColorSpace: 1
    exif:DateTimeDigitized: 2012:06:13 17:54:28
    exif:DateTimeOriginal: 2012:06:13 17:54:28
    exif:ExposureProgram: 2
    exif:ExposureTime: 1/282
    exif:Flash: 24
    exif:FNumber: 14/5
    exif:FocalLength: 77/20
    exif:MeteringMode: 1
    exif:PixelXDimension: 2592
    exif:PixelYDimension: 1936
    exif:SensingMethod: 2
    exif:ShutterSpeedValue: 6845/841
    jpeg:colorspace: 2
    jpeg:sampling-factor: 1x1,1x1,1x1
    signature: 3aecead0329770055dc089c9c9c91a5ee25b599942f05a0f089e53d2170e8ea8
    tiff:Compression: 6
    tiff:JPEGInterchangeFormat: 656
    tiff:JPEGInterchangeFormatLength: 7441
    tiff:Make: Apple
    tiff:Model: iPhone 4
    tiff:XResolution: 72/1
    tiff:YCbCrPositioning: 1
    tiff:YResolution: 72/1
    xap:CreateDate: 2012-06-13T22:12:09Z
    xap:CreatorTool: Adobe Fireworks CS3
    xap:ModifyDate: 2012-06-13T22:12:09Z

However, the verbose information does show

Orientation: RightTop

I am not sure if IM needs the plain Orientation value or the EXIF Orientation value to autocorrect?

But running EXIFTOOL

exiftool -s -ee -g1 -u -n -D 0000221676_0.jpg

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---- ExifTool ----
    - ExifToolVersion                 : 8.71
---- System ----
    - FileName                        : 0000221676_0.jpg
    - Directory                       : .
    - FileSize                        : 135169
    - FileModifyDate                  : 2013:07:17 20:09:08-07:00
    - FilePermissions                 : 644
---- File ----
    - FileType                        : JPEG
    - MIMEType                        : image/jpeg
    - ImageWidth                      : 750
    - ImageHeight                     : 507
    - EncodingProcess                 : 0
    - BitsPerSample                   : 8
    - ColorComponents                 : 3
    - YCbCrSubSampling                : 1 1
---- JFIF ----
    0 JFIFVersion                     : 1 1
    2 ResolutionUnit                  : 1
    3 XResolution                     : 72
    5 YResolution                     : 72
---- XMP-x ----
    - XMPToolkit                      : Adobe XMP Core 4.1-c034 46.272976, Sat Jan 27 2007 22:37:37
---- XMP-tiff ----
    - Make                            : Apple
    - Model                           : iPhone 4
    - Orientation                     : 6
    - XResolution                     : 72
    - YResolution                     : 72
    - ResolutionUnit                  : 2
    - YCbCrPositioning                : 1
    - Compression                     : 6
    - JPEGInterchangeFormat           : 656
    - JPEGInterchangeFormatLength     : 7441
---- XMP-xmp ----
    - CreatorTool                     : Adobe Fireworks CS3
    - ModifyDate                      : 2012:06:13 22:12:09Z
    - CreateDate                      : 2012:06:13 22:12:09Z
---- XMP-exif ----
    - ExposureTime                    : 0.00354609929078014
    - FNumber                         : 2.8
    - ExposureProgram                 : 2
    - DateTimeOriginal                : 2012:06:13 17:54:28
    - DateTimeDigitized               : 2012:06:13 17:54:28
    - ShutterSpeedValue               : 0.00354715946612052
    - ApertureValue                   : 2.79999992194687
    - MeteringMode                    : 1
    - Flash                           : 24
    - FocalLength                     : 3.85
    - ColorSpace                      : 1
    - ExifImageWidth                  : 2592
    - ExifImageHeight                 : 1936
    - SensingMethod                   : 2
---- XMP-dc ----
    - Format                          : image/jpeg
---- Composite ----
    - Aperture                        : 2.8
    - Flash                           : 0
    - ImageSize                       : 750x507
    - ShutterSpeed                    : 0.00354609929078014
    - FocalLength35efl                : 3.85

shows Oriention: 6

So I am not sure why IM is not picking up the EXIF Orientation. It could be a bug.

snibgo wrote:I'm not sure what you are asking. exiftool reports:
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XMP-tiff:Orientation='Rotate 90 CW'

Yep, exiftool does report the orientation, but for the sake of consistency, I want to extract the orientation using ImageMagick tools, so that the value I'm extracting is consistent with what "convert" uses when I later use -auto-orient when converting the image to another size.

A decription of our upload flow might help here. When a user uploads an image, we store the uploaded image as-is, and we also extract the width and height of the image, to store in our database. We also extract orientation (currently using "identify -format '%[EXIF:Orientation]'"), and if the orientation is one that involves a rotaion, we swap the width and height before storing them, so that the dimensions we store in our database match the image's true orientation.

When we serve the image on our site, we use resize the image to our desired size using convert, with the -auto-orient and -strip flags to re-orient the image and then remove its orientation data, if necessary. We need to know what size the image will be before we resize it, though, so that we can write the dimensions in to the page; the image is generated on-the-fly after the page has been rendered.

Right now, because we can't reliably extract the orientation, we sometimes display images with the wrong width and height in their img tags on the page. I could use another tool, like eximtool, to extract the orientation, but if there's ever a mismatch between what exiftool reports and what "convert -auto-orient" acts on, then I'll just end up back in the same situation.

I seems that I can extract the orientation using "identify -verbose", but this extracts a bunch of other things I don't need, and takes a noticeable amount of CPU time doing it, so I'd like to avoid it if possible.

From http://www.imagemagick.org/script/comma ... uto-orient

"This operator reads and resets the EXIF image profile setting 'Orientation' and then performs the appropriate 90 degree rotation on the image to orient the image, for correct viewing."

I do not think that IM knows anything about the XMP-Tiff orientation that one finds with EXIFTOOL, though I am not sure. Thus it would have to be in the EXIF:Orientation field, which is not in your image.

I would suggest you post this issue to the Developers forum and inquire which Orientation value IM uses for -auto-orient. If IM knows about Orientation in the verbose information is that used when there is no EXIF:Orientation? Where does IM find this Orientation value when opening the file?

Although it it not listed as a string format at http://www.imagemagick.org/script/escape.php, this does work to get it:

convert 0000221676_0.jpg -format "%[orientation]" info:
RightTop

I will update the string format documentation tomorrow.

fmw42 wrote:Although it it not listed as a string format at http://www.imagemagick.org/script/escape.php, this does work to get it:

convert 0000221676_0.jpg -format "%[orientation]" info:
RightTop

I will update the string format documentation tomorrow.

Thanks! That looks like exaclty what I'm after.

I might post about this on the developer forum, too, even if it's just to confirm what the expected behaviour is and make sure that the documentation is updated to match that behaviour.

I might post about this on the developer forum, too, even if it's just to confirm what the expected behaviour is and make sure that the documentation is updated to match that behaviour.

I think that is a good idea -- to confirm what Orientation tag is being used by IM.

Legacy ImageMagick Discussions Archive

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Extract non-Exif orientation data from JPEG?

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Re: Extract non-Exif orientation data from JPEG?

Re: Extract non-Exif orientation data from JPEG?

Re: Extract non-Exif orientation data from JPEG?

Re: Extract non-Exif orientation data from JPEG?

Re: Extract non-Exif orientation data from JPEG?