读取MNIST数据集中图像数据文件和图像标签文件并转化成BMP图片和txt格式的标签数据。本程序简单易用，注释清楚。直接运行代码，选择相应文件即可输出BMP图片或txt文件。-The program is used to read the MNIST data set and translate the image data file and image label file into BMP or txt files.

非常简短的mnist文件解析程序,两个函数分别解析image和label两种文件,返回为numpy的array类型,供opencv进一步处理及显示(A very short MNIST file parser. The two functions parse two files of image and label respectively, and return to the array type of numpy for OpenCV to further process and displ