Pixelart Cleanup

When to trigger

• User mentions "halo", "ghost pixels", "semi-transparent fringing", or "alpha cleanup"
• User ran PixelLab and wants to post-process the output before committing assets
• User says sprites look blurry or have faint artifacts around edges

Invocation examples

Single file:

cd scripts/pixelart-cleanup
pnpm start -- -i ../../public/assets/games/my-game/sprite.png -o ./test-samples/output --verbose

Batch folder:

cd scripts/pixelart-cleanup
pnpm start -- -i ../../public/assets/games/my-game/ -o ../../public/assets/games/my-game/ --verbose

(When output == input dir, the cleaned files overwrite in place)

Tuning order

1. Default (--alpha-threshold 32, orphans on, min-size 1) — try this first
2. Specks remain → raise --alpha-threshold 48 or 64
3. Silhouette degraded → lower --alpha-threshold 16
4. Stray clumps remain → --min-orphan-size 3
5. Details disappearing → --no-remove-orphans as last resort

Test samples

• Input: scripts/pixelart-cleanup/test-samples/input/
• Output: scripts/pixelart-cleanup/test-samples/output/
• Reference sprite: bust-1.png (64×96 PixelLab portrait)
  • Expected: halo:~177 orphans:~23

Reading the report

bust-1.png  64x96  visible 3697 -> 3343  halo:177  orphans:23  12ms

• visible before -> after — sanity check; large drop means threshold is too aggressive
• halo — pixels killed by the alpha-threshold pass
• orphans — isolated pixels killed by connected-components pass
• If halo is 0 but you still see artifacts, the specks have alpha ≥ threshold — raise it