Image manipulation from the command line
Get an image's resolution
$ magick identify going-fishing.jpg
going-fishing.jpg JPEG 5422x3648 5422x3648+0+0 8-bit sRGB 12.2217MiB 0.000u 0:00.003Convert an image to a different format
$ magick convert going-fishing.jpg going-fishing.pngResize an image
$ magick convert going-fishing.jpg -resize 800x600 going-fishing-resized.jpgOnly specify width or height
$ magick convert going-fishing.jpg -resize 800x going-fishing-resized-width.jpg
$ magick convert going-fishing.jpg -resize x600 going-fishing-resized-height.jpgBy percentage
$ magick convert going-fishing.jpg -resize 50% going-fishing-resized-percent.jpgCrop an image
$ magick convert going-fishing.jpg -crop 800x600+100+100 going-fishing-cropped.jpgRotate an image
$ magick convert going-fishing.jpg -rotate 90 going-fishing-rotated.jpgAdd a border to an image
$ magick convert going-fishing.jpg -bordercolor black -border 10x10 going-fishing-bordered.jpgAdd text to an image
$ magick convert going-fishing.jpg -gravity South -pointsize 36 -fill white -annotate +0+10 "Going Fishing" going-fishing-text.jpgConvert an image to grayscale
$ magick convert going-fishing.jpg -colorspace Gray going-fishing-grayscale.jpgCreate a thumbnail
$ magick convert going-fishing.jpg -thumbnail 150x150 going-fishing-thumbnail.jpgCombine multiple images into a single image
$ magick convert image1.jpg image2.jpg image3.jpg +append combined-horizontal.jpg
$ magick convert image1.jpg image2.jpg image3.jpg -append combined-vertical.jpgWatermark an image
$ magick convert going-fishing.jpg watermark.png -gravity southeast -geometry +10+10 -composite going-fishing-watermarked.jpg