Package

generator/engraving/validation.py

@@ -9,6 +9,7 @@ import PIL.Image
 import PIL.ImageChops
 
 import generator.engraving.types
+import generator.theme
 
 ENGINE_NAME = 'Vamp Python'
 PAGE_WIDTH = 976
@@ -19,9 +20,10 @@ def check_content(data: bytes, name: str) -> None:
     if image.format != 'PNG' or image.size != (PAGE_WIDTH, PAGE_HEIGHT):
       raise generator.engraving.types.EngravingError(f'{name}: expected a {PAGE_WIDTH}x{PAGE_HEIGHT} PNG page')
     image.load()
-    white = PIL.Image.new('RGBA', image.size, 'white')
-    white.alpha_composite(image.convert('RGBA'))
-    ink = PIL.ImageChops.difference(white.convert('RGB'), PIL.Image.new('RGB', image.size, 'white')).convert('L').point(lambda x: 255 if x > 32 else 0)
+    background = PIL.Image.new('RGB', image.size, generator.theme.rgb('background'))
+    composited = background.convert('RGBA')
+    composited.alpha_composite(image.convert('RGBA'))
+    ink = PIL.ImageChops.difference(composited.convert('RGB'), background).convert('L').point(lambda x: 255 if x > 32 else 0)
     bounds = ink.getbbox()
     if not bounds:
       raise generator.engraving.types.EngravingError(f'{name}: engraver produced a blank page')