Smooth alpha-feathered edges, force PNG format in Gallery, remove unsupported preview param, increase crop padding

app.py

@@ -138,17 +138,26 @@ def mask_iou(m1: np.ndarray, m2: np.ndarray) -> float:
     return float(inter) / float(union) if union > 0 else 0.0
 
 def mask_to_crop(orig_rgb: np.ndarray, mask: np.ndarray) -> np.ndarray:
+    """Crop an RGBA image using a mask with feathered (anti-aliased) edges."""
     h, w = orig_rgb.shape[:2]
     rgba = np.zeros((h, w, 4), dtype=np.uint8)
     rgba[:, :, :3] = orig_rgb
-    rgba[:, :, 3] = (mask * 255).astype(np.uint8)
+    
+    # Create soft alpha channel with Gaussian-feathered edges
+    # This eliminates the harsh jagged pixel boundaries
+    mask_float = mask.astype(np.float32)
+    # Blur the binary mask to create a smooth gradient at edges
+    alpha_soft = cv2.GaussianBlur(mask_float, (7, 7), sigmaX=1.5)
+    # Normalize: keep interior at 255, smoothly fade edges to 0
+    alpha_soft = np.clip(alpha_soft * 255, 0, 255).astype(np.uint8)
+    rgba[:, :, 3] = alpha_soft
     
     ys, xs = np.nonzero(mask)
     if len(ys) == 0:
         return rgba
     y0, y1 = int(ys.min()), int(ys.max())
     x0, x1 = int(xs.min()), int(xs.max())
-    pad = 2
+    pad = 10  # More breathing room around crops
     y0, x0 = max(0, y0 - pad), max(0, x0 - pad)
     y1, x1 = min(h - 1, y1 + pad), min(w - 1, x1 + pad)
     return rgba[y0:y1+1, x0:x1+1]
@@ -351,8 +360,8 @@ with gr.Blocks(title="SAM 3 Asset Extractor") as demo:
                 columns=3,
                 object_fit="contain",
                 height=650,
+                format="png",
                 elem_classes=["gallery-container"],
-                preview=True,
             )
             
     submit_btn.click(fn=extract_assets, inputs=[input_image], outputs=[output_gallery])