Note to myself – Image Magick commands that you will use

Dear future me, here are some ImageMagick commands that you will end up using over an over again and have to look up repeatedly (unless I write them down now, in which case you will surely remember all of them):

  • Convert from from one image format to another (PNG in this case):  mogrify -format png <files>
  • Resize pictures:  convert <input> -resize 25% <output>
  • Add label to the bottom right:  composite label:<text> -gravity southeast <input> <output>
  • Add a white border to the image:  convert -bordercolor White -border 10x10 <input> <output> 
  • Arrange images horizontally such that the spacing between images is just as large as the frame of the whole batch (20px, in this case):  cmd /c "montage preview-1.png preview-2.png preview-3.png -geometry 500X500+10+0 -tile x1 - | convert - -bordercolor White -border 10x20 preview.png" — note the use of CMD here, since Windows PowerShell screws up piping of binary data (“Hey, it’s a string, let’s make it Unicode!”)
  • Cut out the center in a square format:  convert <input> -set option:distort:viewport "%[fx: w>h ? h : w]x%[fx: w>h ? h : w]+%[fx: w>h ? (w - h)/2 : 0]+%[fx: w>h ? 0 : (h - w)/2]" -filter point -distort SRT 0 +repage <output>
  • Cut out the center in a 2/3 format:  convert <input> -set option:distort:viewport "%[fx: w>(3/2*h) ? 3/2*h : w]x%[fx: w>(3/2*h) ? h : 2/3*w]+%[fx: w>(3/2*h) ? (w - 3/2*h)/2 : 0]+%[fx: w>(3/2*h) ? 0 : (h - 2/3*w)/2]" -filter point -distort SRT 0 +repage <output>