2025-12-01

extensions/user_default/retopoflow/scripts/create_thumbnails.py

@@ -0,0 +1,35 @@
+#!/usr/bin/python3
+
+import os
+import png
+import sys
+import glob
+import shutil
+import subprocess
+
+w,h = 120,120
+tempfn = '_temporary.thumb.png'
+
+def same_pngs(fnA, fnB):
+    wA, hA, dA, mA = png.Reader(filename=fnA).read()
+    wB, hB, dB, mB = png.Reader(filename=fnB).read()
+    if (wA, hA) != (wB, hB): return False  # different sizes
+    for rowA, rowB in zip(dA, dB):
+        for colA, colB in zip(rowA, rowB):
+            if colA != colB: return False
+    # not checking meta data (mA == mB)
+    # for example: ignoring the creation timestamp
+    return True
+
+for fullfn in glob.glob('*.png'):
+    if fullfn.endswith('.thumb.png'):
+        # do not thumb the thumb files!
+        continue
+    fullbase, _ = os.path.splitext(fullfn)
+    thumbfn = f'{fullbase}.thumb.png'
+    subprocess.call(f'convert "{fullfn}" -resize {w}x{h} "{tempfn}"', shell=True)
+    if os.path.exists(thumbfn) and same_pngs(tempfn, thumbfn):
+        # pixel data did not change
+        os.remove(tempfn)
+    else:
+        shutil.move(tempfn, thumbfn)