mediapane-diff

A mediapane plugin: compare two images in the pane.

mediapane diff before.png after.png            # side by side, flicker, difference heatmap
mediapane diff a.png b.png --mode heat         # just one of: side, flicker, heat
mediapane diff <(git show HEAD~1:fig.png) fig.png --name fig.png

The views arrive as one series (one gallery entry, stepped with ←/→):

• side by side, labelled A and B
• flicker: A and B alternating at 2 fps, which makes small shifts jump out
• difference: per-pixel absolute difference (the largest over channels) in heat colours over a dimmed A. The scale is stretched to the largest difference, so even a single changed level shows.

It prints a one-line summary (fig.png: 1.33% of pixels differ (max 215/255, mean 2.87), or identical). Animations are compared by their first frame; if the sizes differ, B is scaled to A's size. Exit status: 0 on success, 1 if no pane is reachable, 2 if an input can't be read.

As a git difftool

git config --global difftool.mediapane.cmd 'mediapane diff "$LOCAL" "$REMOTE" --name "$MERGED"'
git difftool -y -t mediapane -- fig.png
git difftool -y -t mediapane HEAD~3 -- '*.png'

For a file that was added or deleted, git passes /dev/null for the missing side, and only the side that exists is shown.

Install

uv tool install mediapane --with mediapane-diff

Development: uv sync && uv run pytest in this directory.