^ 1 Changelog

* 2023-02-06
    * Done

^ 2 convert

^ 2.1 draw

convert -stroke yellow -strokewidth 5 -draw "line 500,300 800,300" \
        -strokewidth 1 -pointsize 12 -draw "text 500,400 '10 um'" \
        draw_ellipse.gif \
        draw_ellipse-bar.gif

^ 2.2 resize

ImageMagick will try to preserve the aspect ratio if you use this command. It will alter the image to fit within a 200×100 area, but the image may not be exactly 200×100. If you want to force the image to become a specific size – even if it messes up the aspect ratio – add an exclamation point to the dimensions:

convert input.jpg -resize 640x320! output.jpg
convert input.jpg -resize 640x320 output.jpg
convert input.jpg -resize 640 output.jpg
convert input.jpg -resize x320 output.jpg

^ 2.3 format

convert input.bmp output.jpg
convert input.bmp -quality 95 output.jpg

^ 2.4 rotate

convert input.jpg -rotate 90 input-rotated.jpg

^ 2.5 change density

convert -units PixelsPerInch input.jpg -density 300x300 output.jpg
convert -units PixelsPerInch input.jpg -density 300 output.jpg

^ 2.6 Watermark

^ 3 montage

montage input1.jpg input2.jpg input3.jpg input4.jpg input5.jpg -tile 3x2 -geometry "64x64>+2+2" montage.jpg

^ 4 identify

identify -units PixelsPerInch -format "Size: %w pixels x %h pixels\nDensity: %x ppi x %y ppi\n" mypic.jpg

Last modified: 2023-02-06