Add AI Spine animation pipeline

normalize_reference.py

@@ -0,0 +1,23 @@
+#!/usr/bin/env python3
+"""Prepare a reference for feature matching without changing its artwork."""
+import argparse
+from pathlib import Path
+from PIL import Image
+
+def main():
+    p = argparse.ArgumentParser()
+    p.add_argument('--input', required=True)
+    p.add_argument('--output', required=True)
+    p.add_argument('--target', type=int, default=1024)
+    a = p.parse_args()
+    im = Image.open(a.input).convert('RGBA')
+    longest = max(im.width, im.height)
+    if longest < a.target:
+        scale = a.target / longest
+        size = (max(1, round(im.width * scale)), max(1, round(im.height * scale)))
+        # Nearest-neighbour preserves pixel-art edges and transparency.
+        im = im.resize(size, Image.Resampling.NEAREST)
+    im.save(a.output)
+    print(f'Reference prepared: {im.width}x{im.height}')
+
+if __name__ == '__main__': main()