python-2.7 - 无法从视频中检测人脸并将其保存为图像

Question

以下是用于从视频(.mp4)中检测人脸的代码。 我需要检测人脸并将其保存为图像。

import cv2
import sys

cascPath = 'haarcascade_frontalface_default.xml'
faceCascade = cv2.CascadeClassifier(cascPath)

video_capture = cv2.VideoCapture('sample.mp4')

while(video_capture.isOpened()):

# Capture frame-by-frame
ret, frame = video_capture.read()

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

faces = faceCascade.detectMultiScale(
    gray,
    scaleFactor=1.1,
    minNeighbors=5,
    minSize=(30, 30),
    flags=cv2.cv.CV_HAAR_SCALE_IMAGE
)

# Draw a rectangle around the faces
for (x, y, w, h) in faces:
    cv2.rectangle(frame, (x, y), (x+w, y+h), (0, 255, 0), 2)

cv2.imshow('Video', frame)

if cv2.waitKey(1) & 0xFF == ord('q'):
    break

video_capture.release()

它在语句 video_capture.isOpened()

处失败

我试过给相对路径还是失败了？

Answer 1

在我将 opencv_ffmpeg300.dll 复制到 c://python2.7 文件夹后，问题就解决了

仅供引用:

下面的代码片段将检测到的人脸保存为单独的图像

crop_img = frame[y:y+h,x:x+w]
cv2.imwrite('E://vijay//frames//frame%d.jpg' %count, crop_img)
count += 1