Harr Cascade CV2 error: (-215) scn == 3 || scn == 4 in function cv::ipp_cvtColor

Question

Just getting into vision programming and running into an issue. Here is my code:

import numpy as np
import cv2

# multiple cascades: https://github.com/Itseez/opencv/tree/master/data/haarcascades

#https://github.com/Itseez/opencv/blob/master/data/haarcascades/haarcascade_frontalface_default.xml
face_cascade = cv2.CascadeClassifier('haarcascade_frontalface_default.xml')
#https://github.com/Itseez/opencv/blob/master/data/haarcascades/haarcascade_eye.xml
eye_cascade = cv2.CascadeClassifier('haarcascade_eye.xml')

cap = cv2.VideoCapture(0)

while 1:
    ret, img = cap.read()
    gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
    faces = face_cascade.detectMultiScale(gray, 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 = eye_cascade.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)
    if cv2.waitKey(1) & 0xFF == ord('q'):
        break

cap.release()
cv2.destroyAllWindows()

I get the error "OpenCV Error: Assertion failed (scn == 3 || scn == 4) in cv::ipp_cvtColor, file C:\projects\opencv-python\opencv\modules\imgproc\src\color.cpp, line 7456 Traceback (most recent call last): File "C:/Users/Peter/PycharmProjects/untitled/FaceDetection.py", line 15, in gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY) cv2.error: C:\projects\opencv-python\opencv\modules\imgproc\src\color.cpp:7456: error: (-215) scn == 3 || scn == 4 in function cv::ipp_cvtColor"

I can find examples of this being resolved when using still images but not a video feed. I checked the img.shape and it was 3 dimentional, so that isnt my issue. Any ideas?

Thanks

Answer 1

Change the:

while 1:

to:

while ret == True:

Hopefully this helps!

Answer 2

Probably 'haarcascade_frontalface_default.xml' is not in the folder with our script.