Python opencv/cvzone – UnboundLocalError

I am trying to make a ar mouse (camera vould detect your hand and than your finger vould be the mouse). But when checking which fingers are up I get an error. When making this program I followed this tutorial: https://www.youtube.com/watch?v=8gPONnGIPgw&t=332s. When doing that I made one thing different which is that I didn’t make a program file called HandTrackingModule.py as he did and than import that but I just imported from cvzone.HandTrackingModule import HandDetector which shoud work the same.

This is the error:

fingers = detector.fingersUp()

in fingersUp return fingers

UnboundLocalError: local variable ‘fingers’ referenced before assignment

this is the code:

import cv2
import numpy as np
import time
import autopy
from cvzone.HandTrackingModule import HandDetector

wCam, hCam = 640, 480
frameR = 100 # Frame Reduction
smoothening = 7
 
pTime = 0
plocX, plocY = 0, 0
clocX, clocY = 0, 0
 
cap = cv2.VideoCapture(0)
cap.set(3, wCam)
cap.set(4, hCam)
detector = HandDetector(detectionCon=0.7,maxHands=1)
wScr, hScr = autopy.screen.size()
 
while True:
    # 1. Find hand Landmarks
    success, img = cap.read()
    img = detector.findHands(img)
    lmList, bbox = detector.findPosition(img)

    # 2. Get the tip of the index and middle fingers
    if len(lmList) != 0:
        x1, y1 = lmList[8][:1]
        x2, y2 = lmList[12][:1]
    
    # 3. Check which fingers are up
    fingers = detector.fingersUp() #------------------this is where the error happens
    print(fingers)
    cv2.rectangle(img, (frameR, frameR), (wCam - frameR, hCam - frameR),
    (255, 0, 255), 2)

    # 4. Only Index Finger : Moving Mode
    if fingers[1] == 1 and fingers[2] == 0:
        # 5. Convert Coordinates
        x3 = np.interp(x1, (frameR, wCam - frameR), (0, wScr))
        y3 = np.interp(y1, (frameR, hCam - frameR), (0, hScr))

        # 6. Smoothen Values
        clocX = plocX + (x3 - plocX) / smoothening
        clocY = plocY + (y3 - plocY) / smoothening
    
        # 7. Move Mouse
        autopy.mouse.move(wScr - clocX, clocY)
        cv2.circle(img, (x1, y1), 15, (255, 0, 255), cv2.FILLED)
        plocX, plocY = clocX, clocY
        
    # 8. Both Index and middle fingers are up : Clicking Mode
    if fingers[1] == 1 and fingers[2] == 1:

        # 9. Find distance between fingers
        length, img, lineInfo = detector.findDistance(8, 12, img)

        # 10. Click mouse if distance short
        if length < 40:
            cv2.circle(img, (lineInfo[4], lineInfo[5]),
            15, (0, 255, 0), cv2.FILLED)
            autopy.mouse.click()

    # 12. Display
    cv2.imshow("Image", img)
    cv2.waitKey(1)

Answer

Your code indentation is wrong.

# 2. Get the tip of the index and middle fingers
if len(lmList) != 0:
    x1, y1 = lmList[8][:1]
    x2, y2 = lmList[12][:1]

    # 3. Check which fingers are up
    fingers = detector.fingersUp() #------------------this is where the error happens
    print(fingers)
    cv2.rectangle(img, (frameR, frameR), (wCam - frameR, hCam - frameR),
    (255, 0, 255), 2)

    # 4. Only Index Finger : Moving Mode
    if fingers[1] == 1 and fingers[2] == 0:
        # 5. Convert Coordinates
        x3 = np.interp(x1, (frameR, wCam - frameR), (0, wScr))
        y3 = np.interp(y1, (frameR, hCam - frameR), (0, hScr))

        # 6. Smoothen Values
        clocX = plocX + (x3 - plocX) / smoothening
        clocY = plocY + (y3 - plocY) / smoothening
    
        # 7. Move Mouse
        autopy.mouse.move(wScr - clocX, clocY)
        cv2.circle(img, (x1, y1), 15, (255, 0, 255), cv2.FILLED)
        plocX, plocY = clocX, clocY
        
    # 8. Both Index and middle fingers are up : Clicking Mode
    if fingers[1] == 1 and fingers[2] == 1:

        # 9. Find distance between fingers
        length, img, lineInfo = detector.findDistance(8, 12, img)

        # 10. Click mouse if distance short
        if length < 40:
            cv2.circle(img, (lineInfo[4], lineInfo[5]),
            15, (0, 255, 0), cv2.FILLED)
            autopy.mouse.click()