Dataset introduction【01】-MNIST

The MNIST data set is a subset of the NIST data set, which contains 60,000 images as training data and 10,000 images as test data. Each image in the MNIST data set represents a number from 0 to 9. The size of the pictures is 28x28, and the numbers will appear in the middle of the pictures. These are grayscale images, so they are a layer of three-dimensional data.

The NIST data set can be downloaded from its official website. Since it is a foreign website, the download may be slow. It contains four parts:
training set images: train-images-idx3-ubyte.gz (9.9 MB, 47 MB ​​after decompression, containing 60,000 samples)
training set labels: train-labels-idx1-ubyte.gz (29 KB , 60 KB after decompression, contains 60,000 labels)
Test set images: t10k-images-idx3-ubyte.gz (1.6 MB, 7.8 MB after decompression, contains 10,000 samples)
Test set labels: t10k-labels-idx1-ubyte. gz (5KB, 10 KB after decompression, contains 10,000 tags)
The picture here is not the picture file we usually see, but a binary file. This dataset stores 60,000 images in a binary format. The label is the real number corresponding to the picture.