opencv 视频、图片转换

# coding=utf-8
import shutil
import cv2
import os
video_path = ‘./test.mp4‘
image_path = ‘./image‘
extract_frame = 20


def extract_frames(video_path, image_path, index):
    """视频转图片"""
    video = cv2.VideoCapture()

    if not video.open(video_path):
        print("can not open the video path")
        exit(1)
    count = 1
    while True:
        success, frame = video.read()
        if frame is None:
            break
        if count % extract_frame == 0:          # 通过调整extract_frame的值来提取图片的帧率
            save_path = ‘{}/{:>03d}.bmp‘.format(image_path, index)
            cv2.imwrite(save_path, frame)
            index += 1
        count += 1
    video.release()
    print("totall save {:d} pics".format(index-1))


def main():
    try:
        shutil.rmtree(image_path)
    except OSError:
        pass
    import os
    os.mkdir(image_path)
    extract_frames(video_path, image_path, 1)


if __name__ == ‘__main__‘:
    main()

# 图片合成视频
def picvideo(path, size):
    filelist = os.listdir(path)  # 获取该目录下的所有文件名
    filelist.sort()

    ‘‘‘
    fps:
    帧率：1秒钟有n张图片写进去[控制一张图片停留5秒钟，那就是帧率为1，重复播放这张图片5次] 
    如果文件夹下有50张 534*300的图片，这里设置1秒钟播放5张，那么这个视频的时长就是10秒
    ‘‘‘
    fps = 5
    # size = (591,705) #图片的分辨率片
    file_path = "./image/" + ‘result‘ + ".avi"  # 导出路径
    fourcc = cv2.VideoWriter_fourcc(‘M‘, ‘J‘, ‘P‘, ‘G‘)  # 不同视频编码对应不同视频格式（例：‘I‘,‘4‘,‘2‘,‘0‘ 对应avi格式 ‘D‘, ‘I‘, ‘V‘, ‘X‘ mp4 png图片）

    video = cv2.VideoWriter(file_path, fourcc, fps, size)

    for item in filelist:
        if item.endswith(‘.jpg‘):  
            item = path + ‘/‘ + item
            img = cv2.imread(item)  # 使用opencv读取图像，直接返回numpy.ndarray 对象，通道顺序为BGR ，注意是BGR，通道值默认范围0-255。
            video.write(img)  # 把图片写进视频

    video.release()  # 释放
    print("转换完成")

picvideo(‘./image‘, (352, 640))