hand tracking system using opencv error:TypeError: handDetector.findHands() missing 1 required positional argument: 'img'

Question

I'm following an online advanced CV course but the code wouldn't run properly for me. These are the error messages I've gotten:

#Traceback (most recent call last):
  #File "C:\Users\lihua\PycharmProjects\AdvancedComputerVision\HandTrackingModule.py", line 60, 
#in <module>
    #main ()

  #File "C:\Users\lihua\PycharmProjects\AdvancedComputerVision\HandTrackingModule.py", line 48, 
#in main
    #img = detector.findHands(img)
#TypeError: handDetector.findHands() missing 1 required positional argument: 'img'

#[ WARN:[email protected]] global D:\a\opencv-python\opencv- 
#python\opencv\modules\videoio\src\cap_msmf.cpp (539) `anonymous- 
#namespace'::SourceReaderCB::~SourceReaderCB terminating async callback

I don't understand what I did wrong as I followed the online tutorial exactly and it seems that it worked out fine with the person in the tutorial

import cv2
import mediapipe as mp
import time

class handDetector ():
    #initialization
    def __init__ (self,mode =False, maxHands =2, detectionCon=0.5,trackCon=0.5 ):
        self.mode = mode
        self.maxHands= maxHands
        self.detectionCon =detectionCon
        self.trackCon = trackCon
        self.mpHands = mp.solutions.hands
        self.hands = self.mpHands.Hands(self.mode,self.maxHands,
                                   self.detectionCon,self.trackCon)
        self.mpDraw = mp.solutions.drawing_utils

    def findHands(self,img,draw =True):
        imgRGB = cv2.cvtColor(img, cv2.COLOR_BGR2RGB)
        results = self.hands.process(imgRGB)
        # print (results.multi_hand_landmarks)

        if results.multi_hand_landmarks:
            for handLms in results.multi_hand_landmarks:
                if draw:
                    self.mpDraw.draw_landmarks(img, handLms, self.mpHands.HAND_CONNECTIONS)
        return img
def main ():
    pTime = 0
    cTime = 0
    cap = cv2.VideoCapture(0)
    detector = handDetector
    while True:
        success, img = cap.read()
        img = detector.findHands(img)

    cTime = time.time()
    fps = 1 / (cTime - pTime)
    pTime = cTime

    cv2.putText(img, str(int(fps)), (10, 70), cv2.FONT_HERSHEY_PLAIN, 3, (225, 0, 225), 3)

    cv2.imshow('Image', img)
    cv2.waitKey(1)

if __name__ == '__main__':
    main ()

Answer 1

You forgot to instantiate the class handDetector in the main function line 31, you have to add () otherwise you pass him the complete object without instantiating it.