Invert Colours

convert input.jpg output.jpg -negate

Make Images Smaller

convert image.jpg -resize 25% output.jpg

Trim images to border

This is generally used for transparrent images.

convert -trim image.png output.png

Make the white of an image transparrent.

convert -transparent white -fuzz 10% input.png output.png

The 'fuzz' option tells the computer that 'close to white' is fine. You might want to use 20% or higher fuzz.

Dropshadow

convert <input file> $ +clone -background black -shadow 50x8+0+5 $ +swap -background none -layers merge +repage <output file>

Convert every jpg in directory to png

mogrify -format png *.jpg

Printing Words

Mass convert

This script converts all jpg files in a directory to svg.

for i in  *jpg
do convert "$i" $(ls "$i" | sed s#jpg\$#svg#)
done

SVG

The above script has crappy results. It's better to use potrace.

$convert input.jpg output.ppm
$potrace -s output.ppm -o svgout.svg

Writing Words

docs

See your installed fonts:

convert -list font

Make na image showing day of the week:

convert -fill blue -font Sauce-Code-Pro-Semibold-Nerd-Font-Complete-Mono -gravity center -pointsize 79 label:$(date +%A) day.png

Make a meme:

convert inputmemeimage.png -font impact -fill white -pointsize 84 -stroke black -strokewidth 3 -gravity north -annotate +0+20 'TOP MEME TEXT' -gravity south -annotate +0+20 'BOTTOM MEME TEXT' outputmemeimage.png

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