# JSON for MNIST

This repo contains two JSON files, `train.json` and `test.json`, which
are a human-readable reproduction of the training and testing data from
the [MNIST database](https://en.wikipedia.org/wiki/MNIST_database). There are
10,000 entries in `train.json` and another 60,000 in `test.json`.

## Formatting

A typical line in either JSON file looks like

`
{"84": [[7, 6]], "185": [[7, 7]], "159": [[7, 8]], "151": [[7, 9]],
"60": [[7, 10]], "36": [[7, 11]], "222": [[8, 6]], "254": [[8, 7], [8, 8],
[8, 9], [8, 10], [9, 12], [9, 14], [9, 15], [9, 16], [9, 19], [9, 20],
[10, 20], [13, 18], [14, 18], [15, 17], [17, 16], [19, 15], [20, 14], [21, 13],
[21, 14], [22, 13], [23, 12], [23, 13], [24, 12], [24, 13], [25, 11], [25, 12],
[26, 11]], "241": [[8, 11]], "198": [[8, 12], [8, 13], [8, 14], [8, 15],
[8, 16], [8, 17], [8, 18], [8, 19]], "170": [[8, 20]], "52": [[8, 21],
[23, 14], [24, 14]], "67": [[9, 6], [10, 14], [10, 15], [10, 16]],
"114": [[9, 7], [9, 9]], "72": [[9, 8]], "163": [[9, 10]], "227": [[9, 11]],
"225": [[9, 13]], "250": [[9, 17]], "229": [[9, 18]], "140": [[9, 21]],
"17": [[10, 11]], "66": [[10, 12]], "14": [[10, 13]],
"59": [[10, 17], [14, 16]], "21": [[10, 18]], "236": [[10, 19]],
"106": [[10, 21]], "83": [[11, 18], [12, 20]], "253": [[11, 19]],
"209": [[11, 20]], "18": [[11, 21], [26, 13]], "22": [[12, 17]],
"233": [[12, 18]], "255": [[12, 19]], "129": [[13, 17]], "238": [[13, 19]],
"44": [[13, 20]], "249": [[14, 17]], "62": [[14, 19]],
"133": [[15, 16], [23, 11]], "187": [[15, 18]], "5": [[15, 19]],
"9": [[16, 15]], "205": [[16, 16]], "248": [[16, 17]], "58": [[16, 18]],
"126": [[17, 15]], "182": [[17, 17]], "75": [[18, 14]], "251": [[18, 15]],
"240": [[18, 16]], "57": [[18, 17]], "19": [[19, 13]], "221": [[19, 14]],
"166": [[19, 16]], "3": [[20, 12]], "203": [[20, 13]],
"219": [[20, 15], [25, 13]], "35": [[20, 16]], "38": [[21, 12]],
"77": [[21, 15]], "31": [[22, 11]], "224": [[22, 12]], "115": [[22, 14]],
"1": [[22, 15]], "61": [[24, 10]], "242": [[24, 11]],
"121": [[25, 10], [26, 10]], "40": [[25, 14]], "207": [[26, 12]], "label": 7}
`

This string is a valid dictionary in Python. Its keys are all integers which
lie between 0 and 255, except for the last key listed, which is `label`. Each
of the integer keys represents a greyscale value between `0` and `255`. The
values for these integer keys are lists of pairs, indicating which pixels in
the image have the corresponding greyscale value. The value associated to the
`label` key is the number that the image is supposed to represent.