CODEWITHSUNDEEP
imageimagemagickimagemagick-convert
Simon Kiely
Simon Kiely

Reputation: 6040

Convert entire folder to greyscale using image magick?

I am trying to convert an entire folder to grayscale, using image magick.

convert *.jpg -colorspace Gray -separate -average

is met with this error : 

convert:  `-average' @ error/convert.c/ConvertImageCommand/3290.

What is the correct command for this?

Upvotes: 3

Views: 4153

Answers (2)

Sadi
Sadi

Reputation: 111

Also, the following can be used in a script - for the context menu of file managers like Dolphin, Nautilus, Nemo, Thunar etc:

for filename in "${@}"; do
    name="${filename%.*}"
    ext="${filename##*.}"
    cp "$filename" "$name"-grayscale."$ext"
    mogrify -colorspace gray "$name"-grayscale."$ext"
    rm "$name"-grayscale."$ext"~
done

Upvotes: 0

Mark Setchell
Mark Setchell

Reputation: 207345

If you have lots of files to process, use mogrify:

magick mogrify -colorspace gray *.jpg

If you have tens of thousands of images and a multi-core CPU, you can get them all done in parallel with GNU Parallel:

parallel -X magick mogrify -colorspace gray ::: *.jpg

Upvotes: 11

Related Questions