Update app.py

app.py

@@ -7,8 +7,12 @@ from part2_visualization import VisualizationHandler
 from part3 import SAMAnalyzer
 import time
 
-# Add a simple progress indicator
+MODEL_PATH = 'sam_vit_h_4b8939.pth'
+
 def download_with_progress(url, filename):
+    if os.path.exists(filename):
+        print(f"Model already exists at {filename}")
+        return
     print(f"Downloading {filename}...")
     start_time = time.time()
     urllib.request.urlretrieve(url, filename)
@@ -16,11 +20,11 @@ def download_with_progress(url, filename):
     print(f"Download completed in {end_time - start_time:.2f} seconds")
 
 # Download SAM model if it doesn't exist
-if not os.path.exists('sam_vit_h_4b8939.pth'):
+if not os.path.exists(MODEL_PATH):
     try:
         download_with_progress(
             'https://dl.fbaipublicfiles.com/segment_anything/sam_vit_h_4b8939.pth',
-            'sam_vit_h_4b8939.pth'
+            MODEL_PATH
         )
     except Exception as e:
         print(f"Error downloading SAM model: {e}")