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[Closed] possible bug with %C and %[compression] with TIFF

Posted: 2018-07-26T09:05:12-07:00
by fmw42
Here is a layered/paged TIFF file.

http://www.fmwconcepts.com/misc_tests/t ... iginal.tif

When using identify -verbose in IM 6.9.10.7 Q16 Mac OSX, it shows compressions of LZW, RLE, RLE

But when using string formats, it shows all the same compressions as the first layer

Code: Select all

convert original.tif -format "%[compression]\n" info:
LZW
LZW
LZW

Code: Select all

convert original.tif -format "%C\n" info:
LZW
LZW
LZW

Re: possible bug with %C and %[compression] with TIFF

Posted: 2018-08-06T18:47:47-07:00
by fmw42
This still seems to be an issue in IM 6.9.10.9 and IM 7.0.8.9 and IM 7.0.8.10 beta.

Re: possible bug with %C and %[compression] with TIFF

Posted: 2018-08-12T06:11:56-07:00
by dlemstra
This issue is caused because the compression differs per channel in a PSD file. The last known compression of a channel will be used for the compression of that layer. And this happens when the pixels of the image are being read. When we ping an image we don't read the pixels.

Re: possible bug with %C and %[compression] with TIFF

Posted: 2018-08-12T09:57:17-07:00
by fmw42
But I had not added -ping to the command. I though that meant that the pixels would be read. Is that not true?

Re: possible bug with %C and %[compression] with TIFF

Posted: 2018-08-12T11:40:39-07:00
by dlemstra
It appears that I misread your issue. This was not only an issue with layered tiff images. Just pushed a patch to resolve this issue.

Re: possible bug with %C and %[compression] with TIFF

Posted: 2018-08-12T11:50:03-07:00
by fmw42
Thanks.

Re: possible bug with %C and %[compression] with TIFF

Posted: 2018-08-14T16:18:42-07:00
by fmw42
This appears to be fixed in Imagemagick 6.9.10.10 and 7.0.8.10