changed output image to rgb to see the contours

detector.py

@@ -70,7 +70,7 @@ def find_bats(allImgs):
 
     for img in allImgs:
         blobs = cv.findContours(img[1], cv.RETR_LIST, cv.CHAIN_APPROX_SIMPLE)[-2]
-        after = img[0].copy()
+        after = cv.cvtColor(img[0].copy(), cv.COLOR_GRAY2RGB)
         # Process the blobs
         for blob in blobs:
             if batDepthMin < cv.contourArea(blob) < batDepthMax:  # Only process blobs with a min / max size 
@@ -83,7 +83,7 @@ def find_bats(allImgs):
                 p_not_bat=f"{probs[0]:.4f}"
                 p_bat=f"{probs[1]:.4f}"
                 if p_not_bat < '0.9' and p_bat > '0.5':
-                    cv.drawContours(after, [box], 0, (0,0,255),1)
+                    cv.drawContours(after, [box], 0, (255,0,0),1)
                     total_bats += 1
         allImgAfter.append(after)