Update app.py

app.py

@@ -2,60 +2,43 @@ import gradio as gr
 from PIL import Image
 import numpy as np
 
-def brightness_to_white_alpha(img, bg=None, invert_opacity=False):
+def brightness_to_white_alpha(img, invert_opacity=False):
     if img is None:
         return None
 
-    # Convert image to RGB and get brightness
-    img = img.convert("RGB")
-    img_np = np.array(img).astype(np.float32)
+    # Step 1: Convert to RGB
+    img_rgb = img.convert("RGB")
+    img_np = np.array(img_rgb).astype(np.float32)
+
+    # Step 2: Calculate brightness (luminance)
     brightness = np.dot(img_np[..., :3], [0.299, 0.587, 0.114])  # shape: (H, W)
 
+    # Step 3: Invert if requested
     if invert_opacity:
         brightness = 255 - brightness
 
-    # Normalize brightness to alpha (0.0–1.0), then scale back to 0–255
-    alpha = (brightness / 255.0).clip(0, 1)
-    alpha = (alpha * 255).astype(np.uint8)
-
-    # Create pure white RGB
-    white = np.ones_like(img_np, dtype=np.uint8) * 255  # shape: (H, W, 3)
-
-    # Combine white RGB and computed alpha
-    white_alpha = np.dstack((white, alpha)).astype(np.uint8)  # shape: (H, W, 4)
-
-    white_img = Image.fromarray(white_alpha, mode="RGBA")
-
-    # If background is provided, overlay white on top
-    if bg:
-        bg = bg.convert("RGBA").resize(white_img.size)
-        white_np = np.array(white_img).astype(np.float32) / 255.0
-        bg_np = np.array(bg).astype(np.float32) / 255.0
-
-        fg_a = white_np[..., 3:4]
-        bg_a = bg_np[..., 3:4]
-        out_a = fg_a + bg_a * (1 - fg_a)
-        out_rgb = (white_np[..., :3] * fg_a + bg_np[..., :3] * bg_a * (1 - fg_a)) / np.maximum(out_a, 1e-6)
+    # Step 4: Normalize to 0–255 alpha
+    alpha = brightness.clip(0, 255).astype(np.uint8)
 
-        result = np.dstack((out_rgb, out_a)).clip(0, 1) * 255
-        return Image.fromarray(result.astype(np.uint8), mode="RGBA")
+    # Step 5: Create solid white RGB image
+    height, width = alpha.shape
+    white_rgb = np.full((height, width, 3), 255, dtype=np.uint8)  # White RGB
 
-    return white_img
+    # Step 6: Combine into final RGBA image
+    white_rgba = np.dstack((white_rgb, alpha))  # shape: (H, W, 4)
+    out_img = Image.fromarray(white_rgba, mode="RGBA")
+    return out_img
 
 # Gradio UI
 iface = gr.Interface(
     fn=brightness_to_white_alpha,
     inputs=[
         gr.Image(type="pil", label="Input Image"),
-        gr.Image(type="pil", label="Optional Background Image"),
         gr.Checkbox(label="Invert Brightness → Alpha", value=False)
     ],
-    outputs=gr.Image(type="pil", label="White with Alpha"),
-    title="🎛️ Brightness to White Alpha Image",
-    description=(
-        "Generates a pure white image where opacity = brightness of input. "
-        "Darker = more transparent, lighter = more opaque. Optional overlay on background."
-    )
+    outputs=gr.Image(type="pil", label="White Image with Brightness-Based Alpha"),
+    title="🕊️ Brightness to Alpha (White Glow Generator)",
+    description="Generates a pure white image where transparency is based on brightness — dark = transparent, light = opaque."
 )
 
 if __name__ == "__main__":