# Sprite Processing

> Use when processing, cropping, splitting, or cleaning up existing sprite images or sprite sheets. Triggers on "crop sprite", "remove background", "split sprite sheet", "make transparent", "process PNG".

- Skill: `freema/sprite-processing` (Agent Skill)
- Install (CLI): `npx skillmds@latest add freema/sprite-processing`
- Raw SKILL.md: https://api.skillmd.com/api/skills/freema/sprite-processing/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: freema (https://skillmd.com/u/freema)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/freema/sprite-processing

---


# Sprite Processing with PixelForge

Use `process_sprite` to clean up existing images into game-ready sprites.

## Single Sprite Processing

Remove background and auto-crop:
```
process_sprite
  inputPath: "raw-enemy.png"
  outputPath: "public/assets/games/rpg/enemy.png"
  background: "chromakey"
  square: true
```

**Prefer `chromakey` background** — uses HSV-based green screen removal. Much cleaner than black/white.

## Split Sprite Sheet

Split a horizontal sprite sheet into individual frames:
```
process_sprite
  inputPath: "animation-sheet.png"
  outputPath: "public/assets/games/rpg/hero"
  split: true
  names: ["idle", "walk-1", "walk-2", "attack"]
  background: "chromakey"
  square: true
```
Outputs: `hero-idle.png`, `hero-walk-1.png`, `hero-walk-2.png`, `hero-attack.png`

## Two-Pass Processing

When sprite sheet has white background but individual sprites have black background:
```
# 1. Split sheet (removes white bg between sprites)
process_sprite
  inputPath: "sheet.png"
  outputPath: "public/assets/sprites/char"
  split: true
  names: ["head", "body", "legs"]
  background: "white"
  square: true

# 2. Remove black bg from each sprite
process_sprite
  inputPath: "public/assets/sprites/char-head.png"
  background: "black"
  threshold: 8
  skipCrop: true
```

## Background Removal Methods

| Background | Method | Best For |
|-----------|--------|----------|
| `chromakey` | HSV green screen | **BEST** — cleanest edges, no artifacts |
| `black` | Compositing equation | Dark-themed sprites |
| `white` | Compositing equation | Light-themed sprites |
| `auto` | Edge detection | Unknown backgrounds |

## Options Reference

| Option | Default | Description |
|--------|---------|-------------|
| `background` | auto-detect | `"chromakey"`, `"black"`, `"white"`, or `"auto"` |
| `threshold` | 20 | Color detection sensitivity (0-255) |
| `square` | false | Pad output to square dimensions |
| `padding` | 2 | Pixels of padding around content |
| `split` | false | Split sheet into individual sprites |
| `names` | 0, 1, 2... | Names for split sprites |
| `skipCrop` | false | Keep original dimensions |
| `skipTransparent` | false | Don't remove background |