Feb
15
2018
python opencv FindFacesByCamera
#-*- coding: utf-8 -*- import cv2 import sys from PIL import Image def CatchUsbVideo(window_name, camera_idx): cv2.namedWindow(window_name) #视频来源,可以来自一段已存好的视频,也可以直接来自USB摄像头 cap = cv2.VideoCapture(camera_idx) #告诉OpenCV使用人脸识别分类器 classfier = cv2.CascadeClassifier("./haarcascade_frontalface_alt2.xml") #识别出人脸后要画的边框的颜色,RGB格式 color = (0, 255, 0) while cap.isOpened(): ok, frame = cap.read() #读取一帧数据 if not ok: break #将当前帧转换成灰度图像 grey = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY) #人脸检测,1.2和2分别为图片缩放比例和需要检测的有效点数 faceRects = classfier.detectMultiScale(grey, scaleFactor = 1.2, minNeighbors = 3, minSize = (32, 32)) if len(faceRects) > 0: #大于0则检测到人脸 for faceRect in faceRects: #单独框出每一张人脸 x, y, w, h = faceRect cv2.rectangle(frame, (x - 10, y - 10), (x + w + 10, y + h + 10), color, 2) #显示图像 cv2.imshow(window_name, frame) c = cv2.waitKey(10) if c == 27: break #释放摄像头并销毁所有窗口 cap.release() cv2.destroyAllWindows() if __name__ == '__main__': if len(sys.argv) != 2: print("Usage:%s camera_id\r\n" % (sys.argv[0])) else: print('press \'esc\' to Exit.') CatchUsbVideo("FindFacesByCamera", int(sys.argv[1]))
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