Add check for image

README.md

@@ -0,0 +1,7 @@
+
+
+Install on Raspberry Pi
+
+https://github.com/superuser789/MediaPipe-on-RaspberryPi/issues/10#issuecomment-1079703581
+
+sudo apt install python3-opencv

tracker.py

@@ -43,14 +43,18 @@ class Tracker(object):
         self.img = img
 
     def detect_face(self):
+        if self.img:
             img, face_bboxs = self.face_detector.findFaces(self.img, draw=self.show_img)
             if face_bboxs:
                 if self.show_img:
+                    self.img = img
                     center = face_bboxs[0]["center"]
                     cv2.circle(self.img, center, 5, (255, 0, 255), cv2.FILLED)
 
                 score = face_bboxs[0]["score"][0]
                 return score >= self.min_face_score
+        else:
+            print('Image not usable')
         return False
 
     def loop(self):