Update app.py

app.py

@@ -1,51 +1,36 @@
 import gradio as gr
 from PIL import Image
 import numpy as np
+import io
 
-def combine_opacity_layers(top_img, bg_img, invert_opacity=False):
-    if top_img is None or bg_img is None:
-        return None
+def brightness_to_opacity(image):
+    # Ensure it's RGB
+    img = image.convert("RGB")
+    img_array = np.array(img)
 
-    # Convert both to RGB and resize
-    top = top_img.convert("RGB")
-    bg = bg_img.convert("RGBA").resize(top.size)
-    top_np = np.array(top).astype(np.float32)
+    # Compute grayscale (luminance)
+    gray = np.dot(img_array[...,:3], [0.299, 0.587, 0.114]).astype(np.uint8)
 
-    # Compute brightness from top image
-    brightness = np.dot(top_np[..., :3], [0.299, 0.587, 0.114])
-    if invert_opacity:
-        brightness = 255 - brightness
-    alpha_top = (brightness / 255.0).clip(0, 1)  # shape (H, W)
+    # Use grayscale as alpha
+    alpha = gray
 
-    # Get alpha from background image
-    bg_np = np.array(bg).astype(np.float32) / 255.0
-    alpha_bg = bg_np[..., 3]  # shape (H, W)
+    # Optional: set RGB to white (or use img_array to preserve color)
+    white_rgb = np.ones_like(img_array) * 255
+    rgba_array = np.dstack((white_rgb, alpha))
 
-    # Multiply alpha channels
-    combined_alpha = (alpha_top * alpha_bg).clip(0, 1)
+    # Convert to Image and return
+    result_img = Image.fromarray(rgba_array.astype(np.uint8), mode="RGBA")
+    return result_img
 
-    # Create output RGBA: white RGB + combined alpha
-    height, width = combined_alpha.shape
-    white_rgb = np.ones((height, width, 3), dtype=np.float32)  # all white
-    out_rgba = np.dstack((white_rgb, combined_alpha)) * 255
-    out_img = Image.fromarray(out_rgba.astype(np.uint8), mode="RGBA")
-    return out_img
-
-# Gradio UI
+# Gradio Interface
 iface = gr.Interface(
-    fn=combine_opacity_layers,
-    inputs=[
-        gr.Image(type="pil", label="Top Brightness-Based Image"),
-        gr.Image(type="pil", label="Base Opacity Image (with alpha)"),
-        gr.Checkbox(label="Invert Top Brightness", value=False)
-    ],
-    outputs=gr.Image(type="pil", label="Combined Opacity Image"),
-    title="🔁 Combine Two Opacity Images (Multiply Alphas)",
-    description=(
-        "Takes two images and multiplies their opacity (alpha). Output is solid white "
-        "with combined alpha values. Useful for stacking brightness masks."
-    )
+    fn=brightness_to_opacity,
+    inputs=gr.Image(type="pil", label="Upload Image"),
+    outputs=gr.Image(type="pil", label="Output (Brightness → Opacity)"),
+    title="Brightness to Opacity Converter",
+    description="This tool converts image brightness into opacity. Bright areas become visible, dark areas become transparent."
 )
 
+# Launch the app
 if __name__ == "__main__":
     iface.launch()