OpenCV Face Recognition Program Crashing

Question

Here's the code (I deleted everything that wasn't important)

closed = False

faceClassifier = cv2.CascadeClassifier('face.xml')
eyeClassifier = cv2.CascadeClassifier('eye.xml')
bodyClassifier = cv2.CascadeClassifier('body.xml')
cap = cv2.VideoCapture(0)
def drawBox():
    while closed == False:
        ret, img = cap.read()
        gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
        faces = faceClassifier.detectMultiScale(img, 1.3, 5)
        for (x,y,w,h) in faces:
            cv2.rectangle(img,(x,y),(x+w,y+h),(255,0,0),2)
            roi_gray = gray[y:y+h, x:x+w]
            roi_color = img[y:y+h, x:x+w]

            eyes = eyeClassifier.detectMultiScale(roi_gray)
            for (ex,ey,ew,eh) in eyes:
                cv2.rectangle(roi_color,(ex,ey),(ex+ew,ey+eh),(0,255,0),2)
        cv2.imshow('img',img)

def stopProgram():
    closed = True

tkWindow = Tk()  
tkWindow.geometry('800x800')  
tkWindow.title('Machine Learning Face Detection')



button = Button(tkWindow,
text = 'Stop Program',
command = stopProgram)  
button.pack()  

button = Button(tkWindow,
text = 'Start Program',
command = drawBox)  
button.pack() 

tkWindow.mainloop()
cap.release()
cv2.destroyAllWindows()

As soon as I hit the start program error, the camera window opens gray and then it crashes. Anyone have any idea why? I can't figure it out, but it was working before I tried to implement the stop button.

score 0 · Answer 1 · answered Mar 12 '20 at 00:28

The first problem is that you didn't mark closed as a global variable in your functions drawBox and stopProgram. Other problem is the while loop in drawBox, which will cause the program to stop responding, rendering "Stop Program" button unusable. You need to use tkWindow.after. Here's an example of displaying video frames from cv2.VideoCapture in tkWindow.

OpenCV Face Recognition Program Crashing

1 Answers1