Update app.py

app.py

@@ -343,11 +343,10 @@ def generate_certificate(certificate_model, first_name, last_name):
     # Date of certification
     d.text((1480, 1170), str(date.today()), fill="black", anchor="mm", font=date_font)
 
-    im_temp = im.load()
-    background = Image.new("RGB", im.size, (255, 255, 255))
-    background.paste(im_temp, mask=im_temp.split()[3]) # 3 is the alpha channel
-    
-    pdf = background.save("certificate"+".pdf")
+    rgba = im
+    rgb = Image.new('RGB', im.size, (255, 255, 255))  # white background
+    rgb.paste(rgba, mask=rgba.split()[3]) # 3 is the alpha channel
+    pdf = rgb.save("certificate.pdf", 'PDF', resolution=100.0)    
 
     return im, pdf