Update app.py

app.py

@@ -15,6 +15,7 @@ import re
 import matplotlib.pyplot as plt
 import io
 import base64
+from PIL import Image
 
 # === Temp file cleanup ===
 for pattern in ["/tmp/*.wav", "/tmp/*.mp3"]:
@@ -161,7 +162,7 @@ def generate_user_chart(user, metric):
     plt.savefig(buf, format="png")
     plt.close(fig)
     buf.seek(0)
-    return f"data:image/png;base64,{base64.b64encode(buf.read()).decode()}"
+    return Image.open(buf)
 
 def tutor_feedback(audio_file, language, nickname):
     if not audio_file or not os.path.exists(audio_file):