Wrong exif:ISOSpeedRatings value

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Wrong exif:ISOSpeedRatings value

Post by brooksrbrown »

I am getting the wrong exif value for ISOSpeedRatings for a particular test file. I've looked over the file in a binary editor, and the structure of the IFD seems correct. Other software reports the correct value, 138, but ImageMagick reports 1 when I use identify -verbose.

I haven't seen any incorrect values for ISOSpeedRatings for other files. Hopefully, you can download the sample file from https://www.dropbox.com/s/7nqbihosjr3hfw3/P1290018.TIF.

I am running on Mac OS 10.7, and downloaded ImageMagick from MacPorts.

I've looked at the 6.8.6-7 source code, properties.c, and can't spot the problem.

Best regards,
Brooks Brown
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Re: Wrong exif:ISOSpeedRatings value

Post by fmw42 »

I can confirm on IM Q16 Mac OSX that the verbose info reports 1 for ISOSpeedRatings

Also using string formats returns 1 as below

convert P1290018.TIF -format "%[EXIF:ISOSpeedRatings]" info:

Using EXIFTOOL, it reports

34855 ISO : 138

So IM is likely looking for the wrong EXIF name or the wrong EXIF tag number
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Re: Wrong exif:ISOSpeedRatings value

Post by magick »

Thanks to Dirk we now know that the ISO attribute is a short array rather than a single short value. We'll have a patch to fix this problem within a few days.
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