通过USB摄像头来获取图象,保存图片,能基本实现,是初学者不可多得的一个学习样本-Head through the USB camera to obtain images, save images, can be basically achieved by learners, a learning sample rare

打开视频文件，获取视频关键帧另存为bmp图片-Open video file to get video key frame saved as bmp image