Batch-convert pictures in command line

Question

I would like to convert a large number of pictures in Konsole. I need pictures resized in order to make a video.

I can do it for one picture; I am satisfied with this command:

convert video000001.png -filter Lanczos -resize 50% toto000001.jpeg

So my question is how can treat the case with a lot of pictures?

Answer 1

You can do it with a simple script. Just create a folder with all the images you want to convert and launch the following script in the same folder :

img_convert.sh

#!/bin/bash 

FILES=*.png
mkdir -p ./converted
for i in $FILES 
do 
        echo "Processing image $i..." 
        /usr/bin/convert "$i" -filter Lanczos -resize 50% ./converted/converted_"$i".jpeg
done 

---

Edit:

@pzkpfw pointed out you can simply run this command in your shell for the same result :

for i in *.png; do convert "$i" -filter Lanczos -resize 50% converted_"$i".jpeg; done;

Answer 2

Best solution, to my knowledge, is mogrify.

ImageMagick

If it's not already installed:

sudo apt-get install imagemagick

then, in the directory where your .png files are located:

mogrify -resize 50% *.png

Good luck!