使用opencv从视频中提取灰度图像

Question

我正在尝试从视频中提取图像（帧）并将它们保存在特定位置。我编写了以下代码，它可以很好地提取彩色图像。

extractFrames(srcPath,dstPathColor)

但是，当我想要提取灰度图像时 (extractFrames(srcPath,dstPathColor,gray=True)，只有一张图像被写入目标文件夹并且代码停止

import numpy as np
import cv2
print('OpenCV version: '+cv2.__version__)
import matplotlib as plt

def extractFrames(srcPath,dstPath,gray=False):
    # gray = true writes only grayscale images of the video
    
    cap = cv2.VideoCapture(srcPath)

    # check if camera opened successfully
    if (cap.isOpened() == False):
        print("Error reading video file")

    try:
        frameCount = 1
        while(cap.isOpened()):
            
            ret, frame = cap.read()

            if ret == True:

                if gray==True:
                    gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
                    cv2.imwrite(dstPath+'grayframe'+str(frameCount)+'.jpg',gray)
                    
                else:
                    cv2.imwrite(dstPath+'colorframe'+str(frameCount)+'.jpg',frame)
                                
                frameCount += 1

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

            # if frame is read correctly, ret is True
            else:
                print("Can't retrieve frame - stream may have ended. Exiting..")
                break

    except:
        print("Video has ended.")

    cap.release()
    cv2.destroyAllWindows()
    

vidName = 'scale_calib2.avi'
srcPath = vidName;
dstPathColor = 'Extracted Images\Color\'
dstPathGray = 'Extracted Images\Gray\'

#extractFrames(srcPath,dstPathColor)
#print('Finished extracting color images from video')

extractFrames(srcPath,dstPathGray,gray=True)
print('Finished extracting gray images from video')

输出：

Video has ended.
Finished extracting gray images from video

我该如何解决这个问题？

Answer 1

终于发现问题出在命名错误上。我将 gray 用于灰度图像的图像容器和函数 extractFrames

中的布尔参数

使用opencv从视频中提取灰度图像

Extracting grayscale images from a video using opencv

video

grayscale

opencv-python