Is there any command to check compression type of a file.

[punith8626]

Hello,

Is there any command to check compression type of a file.
I have some files that are corrupted and i need to use alternative for this.How can I check whether images is looking at it without using convert command ?

Example:
I have a files with old JPEG compression type and I am not able to convert those files,Hence I need to use other convertors based on Image corrupted or not.

Could you help me on this?

[fmw42]

IM can tell you the compression type if it can read the file using identify -verbose yourimage. Somewhere listed there will be the compression. Current versions of IM can tell you that more directly from %[compression]. See http://www.imagemagick.org/script/escape.php

But if IM cannot read the file due to its having an old JPEG format that libjpeg does not support, then it won't be able to tell you the compression. Perhaps you can use EXIFTOOL to tell you that information.

[GeeMack]

Current versions of IM can tell you that more directly from %[compression]. See http://www.imagemagick.org/script/escape.php

That is how it's described under "Long Form Attribute Percent Escapes" at THIS link, but I'm using IM 7.0.4-3 on Windows 10 64, and when I run this command...

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magick example.jpg -format "%[compression]" info:

... it produces this warning...

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magick: unknown image property "%[compression]" @ warning/property.c/InterpretImageProperties/3822.

This command will still output the compression type for me...

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magick example.jpg -format "%[C]" info:

[fmw42]

Works fine for me on (Mac OSX SnowLeopard) IM 6.9.7.3 but fails in IM 7.0.3.4. So it seems to be an issue of not getting folded over to IM 7 or being lost in some recent release.

IM 6

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convert logo.tif -format "%[compression]" info:

JPEG

IM 7

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magick logo.tif -format "%[compression]" info:

magick: unknown image property "%[compression]" @ warning/property.c/InterpretImageProperties/3822.