Update app.py

app.py

@@ -12,30 +12,30 @@ import gradio as gr
 
 # Function to convert image to sketch
 def convert_to_sketch(img, blur_strength, brightness, contrast):
-    # Convert PIL Image to numpy array
+    # Convert PIL Image to numpy array (BGR format for OpenCV)
     img = np.array(img)
-
-    # Convert the image to grayscale
-    img_gray = cv2.cvtColor(img, cv2.COLOR_RGB2GRAY)  # Use RGB2GRAY for PIL images
-
+    
+    # Convert the image to grayscale (use RGB2GRAY for PIL images)
+    img_gray = cv2.cvtColor(img, cv2.COLOR_RGB2GRAY)
+    
     # Invert the grayscale image
     img_inverted = cv2.bitwise_not(img_gray)
-
+    
     # Apply Gaussian blur to the inverted image
     img_blur = cv2.GaussianBlur(img_inverted, (blur_strength, blur_strength), sigmaX=0, sigmaY=0)
-
+    
     # Blend the grayscale and blurred inverted images to create the sketch effect
     img_blend = cv2.divide(img_gray, 255 - img_blur, scale=256)
-
+    
     # Create a white background
     white_background = 255 * np.ones_like(img_blend)
-
+    
     # Add the blended image to the white background
     sketch_with_bg = cv2.addWeighted(img_blend, 1, white_background, 1, 0)
-
+    
     # Adjust brightness and contrast
     sketch_with_bg = adjust_brightness_contrast(sketch_with_bg, brightness, contrast)
-
+    
     return sketch_with_bg
 
 # Function to adjust brightness and contrast
@@ -49,8 +49,18 @@ def sketch_interface(image, blur_strength, brightness, contrast):
     # Convert the input image to a sketch with adjustments
     sketch = convert_to_sketch(image, blur_strength, brightness, contrast)
 
+    # Check if the sketch image is non-empty
+    if sketch is None or sketch.size == 0:
+        print("Error: Sketch is empty!")
+        return None
+
     # Convert the processed numpy array back to a PIL Image
     output_image = Image.fromarray(sketch)
+    
+    # Ensure the output image is valid
+    if output_image is None:
+        print("Error: Output image is None!")
+        return None
 
     # Return the processed sketch image
     return output_image