EMNIST dataset + speedup *MNIST preprocessing #334
Merged
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I would like to add support for the recently released EMNIST dataset (https://www.nist.gov/itl/iad/image-group/emnist-dataset)
The data format is similar to
MNIST
so I subclassedMNIST
(likeFashionMNIST
did before). There are 6 splits in the dataset and everything is zipped up inside a single archive, which is why I had to override__init__
anddownload
.I also noticed that
read_image_file
currently parses data byte by byte, which is very slow. Usingnp.frombuffer
speeds up preprocessing by a factor 1000x (so preprocessing takes < 1sec instead of several minutes).