使用opencv 進行人臉識別

在Pycharm中新建python腳本，輸入如下代碼

import cv2


filename = '/home/utryjc/Pictures/timg.jpeg'


def detect(filename):

    face_cascade = cv2.CascadeClassifier('/home/utryjc/opencv-3.2.0/data/haarcascades_cuda/haarcascade_frontalface_default.xml')

    img = cv2.imread(filename)

    gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)

    faces = face_cascade.detectMultiScale(gray, 1.3, 5)

    for (x, y, w, h) in faces:
        img = cv2.rectangle(img, (x, y), (x+w, y+w), (255, 0, 0), 2)
    cv2.namedWindow('Vikings Detected!!')

    cv2.imshow('Vinkings Detected', img)

    cv2.imwrite('/home/utryjc/Pictures/viking.jpg', img)

    cv2.waitKey(0)

detect(filename)

 剛開始把gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)寫成了gray = cv2.cvtColor(img, cv2.COLOR_BAYER_BG2BGR)

出現問題：OpenCV Error: Assertion failed (scn == 1 && (dcn == 3 || dcn == 4)) in demosaicing, file /tmp/binarydeb/ros-kinetic-opencv3-3.3.1/modules/imgproc/src/demosaicing.cpp, line 1651
Traceback (most recent call last):

將參考書中的 img = cv2.imread(filename)改爲img = cv2.imread(filename, 0)即可