Auteur Sujet: Batch converting PNG to JPG with convert from the ImageMagick suite  (Lu 5947 fois)

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Hors ligne melodie

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The convert command found on many Linux distributions is installed as part of the ImageMagick suite. Here's the bash code to run convert on all PNG files in a directory and avoid that double extension problem:

for img in *.png; do
    convert "$filename.png" "$filename.jpg"

This is the one I just used, I ended with both png and jpg files in the same directory, which was the perfect result.

I have a couple more solutions.

The simplest solution is like most already posted. A simple bash for loop.

for i in *.png ; do convert "$i" "${i%.*}.jpg" ; done
For some reason I tend to avoid loops in bash so here is a more unixy xargs approach, using bash for the name-mangling.

ls -1 *.png | xargs -n 1 bash -c 'convert "$0" "${0%.*}.jpg"'
The one I use. It uses GNU Parallel to run multiple jobs at once, giving you a performance boost. It is installed by default on many systems and is almost definitely in your repo (it is a good program to have around).

ls -1 *.png | parallel convert '{}' '{.}.jpg'
The number of jobs defaults to the number of processes you have. I found better CPU usage using 3 jobs on my dual-core system.

ls -1 *.png | parallel -j 3 convert '{}' '{.}.jpg'
And if you want some stats (an ETA, jobs completed, average time per job...)

ls -1 *.png | parallel --eta convert '{}' '{.}.jpg'
There is also an alternative syntax if you are using GNU Parallel.

parallel convert '{}' '{.}.jpg' ::: *.png
And a similar syntax for some other versions (including debian).

parallel convert '{}' '{.}.jpg' -- *.png

More on the above linked page.
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