Update app.py

app.py

@@ -147,7 +147,7 @@ def linscale(linear):
 
 def remove_bg(fl, count):
     global fl_
-    fr = cv2.imread(fl)
+    fr = cv2.imread(fl).astype(np.uint8)
     
     b = 1
     element = cv2.getStructuringElement(cv2.MORPH_RECT, (2 * b + 1, 2 * b + 1), (b, b))
@@ -175,7 +175,7 @@ def remove_bg(fl, count):
 
     if count % 2: # odd: is photo without the flash
         fr_mask = cv2.cvtColor(cv2.imread(fl_).astype(np.uint8), cv2.COLOR_BGR2GRAY)
-        fr_mask = fr_diff - fr_mask
+        fr_mask = (fr_diff - fr_mask).astype(np.uint8)
 
         m = cv2.inRange(fr, np.array([240,240,240]), np.array([255,255,255]))
         fr[m>0] = (239,239,239)