Update app.py

app.py

@@ -237,16 +237,16 @@ def generate_pdf_report(original_img: Image.Image, mask: np.ndarray, overlay: Im
         pdf.set_font("helvetica", "I", 10)
         pdf.cell(text="This report was generated by DR Analysis System", new_x="LMARGIN", new_y="NEXT", align='C')
         
-        # Get PDF as bytes
-        pdf_output = pdf.output()
-        if isinstance(pdf_output, str):
-            return pdf_output.encode('latin1')
-        return pdf_output
+        # Get PDF as bytes - this is the critical fix
+        pdf_bytes = pdf.output(dest='S').encode('latin1')
+        return pdf_bytes
     
     except Exception as e:
         st.error(f"PDF generation failed: {str(e)}")
         return None
 
+
+
 # ====================== MAIN APP ======================
 def main():
     st.set_page_config(layout="wide")
@@ -325,6 +325,7 @@ def main():
                         "image/png"
                     )
                 
+                # In your main app where you create the download button:
                 with col2:
                     # Generate and download PDF report
                     pdf_bytes = generate_pdf_report(
@@ -336,12 +337,15 @@ def main():
                         seg_results['bright_area'],
                         seg_results['red_area']
                     )
-                    st.download_button(
-                        "Download Full Report",
-                        data=pdf_bytes,
-                        file_name="dr_diagnosis_report.pdf",
-                        mime="application/pdf"
-                    )
+                    if pdf_bytes is not None:
+                        st.download_button(
+                            "Download Full Report",
+                            data=pdf_bytes,
+                            file_name="dr_diagnosis_report.pdf",
+                            mime="application/pdf"
+                        )
+                    else:
+                        st.warning("Failed to generate PDF report")
 
     except Exception as e:
         st.error(f"Error processing image: {str(e)}")