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STUART

Member

From: Seattle, WA

Registered: 2010-08-19

Posts: 52

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ImageMagick convert hanging when downscaling images

When I try to convert an image to a smaller image using convert (eg. convert big.png -resize 128x128> small.png), the command just sits there and never completes.

This is with imagemagick 7.0.8.34-1. I have an AMD GPU and CPU, if that matters.

Last edited by STUART (2019-03-22 02:19:34)

jamespharvey20

Member

Registered: 2015-06-09

Posts: 129

Re: ImageMagick convert hanging when downscaling images

I'm assuming you're using mesa and opencl-mesa.  If so, try installing the AUR package "opencl-amd".  It extracts the OpenCL portion only from the proprietary driver, and allows it to run on top of mesa.

Then, try running "OCL_ICD_VENDORS=amdocl64 convert ..."

Or, you could also try AUR package "intel-opencl-runtime" and run "OCL_ICD_VENDORS=intel convert ..."

"opencl-mesa" has had a bug where converting would fail, saying "Error: X unsupported relocations".  I'm guessing a mesa or ImageMagick change has made that bug start just hanging.

See: https://github.com/ImageMagick/ImageMagick/issues/1366

If it's this bug, ImageMagick says it's not their bug, but has failed to explain why the only program this seems to happen on is ImageMagick.  And, I couldn't get mesa to comment on this either.  See https://lists.freedesktop.org/archives/ … 15548.html

EDIT: I just remembered your hat icon, and that you were an upstream reporter of the "unsupported relocations" bug.  As you'll see in my upstream bug, although the patch they gave you seemed to help you, it didn't for a lot of other people.  So, I'd still try "opencl-amd".

Last edited by jamespharvey20 (2019-03-22 02:47:40)

Brocellous

Member

Registered: 2017-11-27

Posts: 162

Re: ImageMagick convert hanging when downscaling images

Sanity check, are you using the right invocation of convert? You wrote "convert big.png -resize 128x128> small.png" but convert requires the input and output files as arguments, e.g. "convert big.png -resize 128x128 small.png". Though I just tried the malformed command myself and it gives me an error instead of hanging. You say that big to small hangs, but do other convert operations work for you?