Allow 3 channel images only

app.py

@@ -40,7 +40,7 @@ with st.spinner("Wait for loading a model..."):
 # Create a canvas component.
 image = None
 if image_path:
-    image = Image.open(image_path)
+    image = Image.open(image_path).convert("RGB")
 canvas_height, canvas_width = 600, 600
 pos_color, neg_color = "#3498DB", "#C70039"
 st.title("Canvas:")