Rich git diffs for images on the command line

!README.md

If you use a terminal emulator that supports imgcat (most commonly and famously iTerm 2 implements it), drop this script into your path and add the attached snippet to your .gitignore to generate visual diffs in your Git commandline.

Derived from https://til.hashrocket.com/posts/n44hnf0z99-show-better-image-diff-on-git

Prerequisites

• Image-capable terminal emulator
• imgcat implementation for your emulator in your path
• GraphicksMagick available in your path (an ImageMagick clone, minus the security flaws)

.gitconfig

[diff "image"]
        textconv = imgcat
        command = imgdiff

imgdiff

#!/bin/bash

echo "$1"
if [[ -f "$1" ]] && [[ -f "$2" ]]; then
  gm compare -highlight-style apply -highlight-color magenta -file png:- "$2" "$1" | gm montage -background transparent -geometry +4 "$2" - "$1" png:- | imgcat
else
  if [[ -f "$1" ]]; then
    echo "+ Image added"
    imgcat "$1"
  else
    echo "- Image removed"
    imgcat "$2"
  fi
fi

exit 0