add online demo

app.py

@@ -34,11 +34,11 @@ if __name__ == '__main__':
     # # Change back to the previous directory
     # os.system("cd ..")
 
-    # Install Segment Anything repository from GitHub
-    os.system("pip install git+https://github.com/facebookresearch/segment-anything.git")
-
-    # Download the model checkpoint
-    os.system("curl -o ./checkpoints/sam_vit_b_01ec64.pth https://dl.fbaipublicfiles.com/segment_anything/sam_vit_b_01ec64.pth")
+    import subprocess 
+    import sys
+    subprocess.check_call([sys.executable, 'pip', 'install', 'git+https://github.com/facebookresearch/segment-anything.git']) 
+    subprocess.check_call([sys.executable, 'curl', '-o', './checkpoints/sam_vit_b_01ec64.pth', 'https://dl.fbaipublicfiles.com/segment_anything/sam_vit_b_01ec64.pth']) 
+    # os.system("curl -o ./checkpoints/sam_vit_b_01ec64.pth https://dl.fbaipublicfiles.com/segment_anything/sam_vit_b_01ec64.pth")
 
     import argparse
     from demo.UI import Main_ui