Update app.py

app.py

@@ -149,8 +149,16 @@ def process_single_image(image, width, height, maintain_aspect, png_bg_option, c
             except:
                 custom_color = (255, 255, 255)  # Default to white if invalid
         
-        # Check if image is PNG
-        is_png = hasattr(pil_image, 'format') and pil_image.format == 'PNG'
+        # Check if image is PNG - improved detection
+        # In Gradio, uploaded images often lose format info, so we assume PNG if it has transparency
+        is_png = (hasattr(pil_image, 'format') and pil_image.format == 'PNG') or \
+                 (pil_image.mode in ('RGBA', 'LA')) or \
+                 (hasattr(pil_image, 'info') and 'transparency' in pil_image.info)
+        
+        # For PNG background selection, we should always apply the background choice
+        # regardless of original format when PNG options are selected
+        if png_bg_option != "auto":
+            is_png = True  # Force PNG treatment for non-auto options
         
         # Resize image
         resized_image = resizer.resize_image(
@@ -192,8 +200,16 @@ def process_folder_images(files, width, height, maintain_aspect, png_bg_option,
                 # Open image
                 image = Image.open(file.name)
                 
-                # Check if image is PNG
-                is_png = file.name.lower().endswith('.png')
+                # Check if image is PNG - improved detection
+                is_png = file.name.lower().endswith('.png') or \
+                         (hasattr(image, 'format') and image.format == 'PNG') or \
+                         (image.mode in ('RGBA', 'LA')) or \
+                         (hasattr(image, 'info') and 'transparency' in image.info)
+                
+                # For PNG background selection, we should always apply the background choice
+                # regardless of original format when PNG options are selected
+                if png_bg_option != "auto":
+                    is_png = True  # Force PNG treatment for non-auto options
                 
                 # Resize image
                 resized_image = resizer.resize_image(
@@ -252,8 +268,16 @@ def process_zip_file(zip_file, width, height, maintain_aspect, png_bg_option, cu
                             file_path = os.path.join(root, file)
                             image = Image.open(file_path)
                             
-                            # Check if image is PNG
-                            is_png = file.lower().endswith('.png')
+                            # Check if image is PNG - improved detection
+                            is_png = file.lower().endswith('.png') or \
+                                     (hasattr(image, 'format') and image.format == 'PNG') or \
+                                     (image.mode in ('RGBA', 'LA')) or \
+                                     (hasattr(image, 'info') and 'transparency' in image.info)
+                            
+                            # For PNG background selection, we should always apply the background choice
+                            # regardless of original format when PNG options are selected
+                            if png_bg_option != "auto":
+                                is_png = True  # Force PNG treatment for non-auto options
                             
                             # Resize image
                             resized_image = resizer.resize_image(