Optimize bg.png conversion without scaling and with correct color mapping

process_cover.py

@@ -3,20 +3,41 @@ from PIL import Image
 # Open the new cover image
 img = Image.open('bg.png')
 
-# Resize to 128x128 to ensure maximum 256 unique tiles
-img = img.resize((128, 128), Image.Resampling.LANCZOS)
+# Convert to grayscale first to get raw intensity values
+img_gray = img.convert('L')
 
-# Create a black 160x144 background
-bg = Image.new('L', (160, 144), color=0)
+# Create a new indexed image with the exact Game Boy palette mapping
+# 0 = White, 1 = Light Gray, 2 = Dark Gray, 3 = Black
+final_img = Image.new('P', img_gray.size)
 
-# Paste the resized image in the center
-bg.paste(img, (16, 8))
+# Set the palette
+palette = [
+    255, 255, 255, # 0: White
+    170, 170, 170, # 1: Light Gray
+    85,  85,  85,  # 2: Dark Gray
+    0,   0,   0    # 3: Black
+]
+palette += [0] * (256 * 3 - len(palette))
+final_img.putpalette(palette)
 
-# Quantize to 4 colors (indexed mode 'P') for png2asset
-final_img = bg.quantize(colors=4)
+# Map the grayscale pixels to palette indices (0-3)
+# Darker pixels get higher indices (closer to 3/Black), lighter get lower indices (closer to 0/White)
+raw_pixels = list(img_gray.getdata())
+mapped_pixels = []
+for p in raw_pixels:
+    if p > 200:
+        mapped_pixels.append(0) # White
+    elif p > 120:
+        mapped_pixels.append(1) # Light Gray
+    elif p > 55:
+        mapped_pixels.append(2) # Dark Gray
+    else:
+        mapped_pixels.append(3) # Black
+
+final_img.putdata(mapped_pixels)
 
 # Save the resulting image
 final_img.save('title_bg.png')
-print("title_bg.png created successfully (160x144, indexed).")
+print("title_bg.png created successfully with correct color indexing.")