Game Image Asset Pipeline

Game Image Asset Pipeline

Use this skill to turn generated images into clean game assets quickly and repeatedly.

1) Lock Target Asset Spec

Before running any script, confirm:

1. Output size (for example 256x256, 512x512)
2. Output format (PNG with alpha)
3. Framing rule (tight crop vs extra padding)
4. Whether watermark/logo cleanup is required

Only run watermark removal on images you are allowed to modify.

2) Run Baseline Pipeline

Use:

python3 scripts/build_icon.py INPUT_IMAGE OUTPUT_IMAGE \
  --size 256 \
  --watermark-corners br

Default behavior:

1. Estimate plain background color from border pixels
2. Remove connected background region
3. Remove bright low-saturation corner watermark components
4. Crop to remaining non-transparent subject
5. Resize and center to square transparent canvas

3) Tune Parameters When Needed

Use these first-line adjustments:

1. Increase --bg-threshold when background residue remains
2. Decrease --bg-threshold when foreground edges are cut
3. Increase --wm-value-threshold to remove fewer bright regions
4. Increase --wm-sat-threshold to remove more grayscale watermark pixels
5. Change --watermark-corners (tl,tr,bl,br,all,none) based on watermark position
6. Use --padding to control empty margin in final icon

If watermark overlaps the character itself, do not over-clean with thresholds; keep the script conservative and perform manual retouch for that region.

4) Validate Output

After generation, verify:

1. Output size matches spec exactly
2. Transparent background has no halo in game UI
3. Watermark is gone or below visibility threshold
4. Subject is centered and not clipped

Resource Map

1. scripts/build_icon.py: end-to-end icon conversion script (Pillow only).
2. references/parameter-tuning.md: parameter decision guide and scenario presets.