mnist_reader

mnist_reader gives a simple and easy way to read and store the mnist database in C++.

Mnist is a database of hand writing numbers used to test and improve image recognition programs.

See : http://yann.lecun.com/exdb/mnist/

How to use it

1. Download the repository

Download the repository with your browser or with git using :

git clone https://github.com/QuentinP-dev/mnist_reader.git

2. Build the mnist_reader library

Use the CMakeLists.txt to create the mnist_reader library :

(example for a Linux system)

cmake CMakeLists.txt -G Unix\ Makefiles -B conf/
cd conf/
cmake --build .
cmake --install .

By default, the library, documentation and examples will be installed in the cmake root folder in a subdirectory named mnist_reader-x.y . (Where x and y are the major and minor version of the lib).

You can pass options to the cmake command using -D (see man cmake)

Option	meaning	default value	added suffix
BUILD_DOC	Build the documentation using doxygen	OFF
BUILD_EXAMPLE	Build a little example	OFF
C++_STATIC_LIB	Build using the static C++ library	OFF	ON: -csl
MNIST_STATIC_CLASS	Use the mnist_reader as a static class	OFF	ON: -stc
MNIST_SUPER_CLASS	Use the mnist_reader as a super class	OFF	ON: -suc
BUILD_MODE	If DEBUG, add debugging flags to the output library	RELEASE	ON: -d
LIBRARY_TYPE	The type of the output library	STATIC	ON: .a OFF: .so or .dll

So if you call cmake with the following line :

cmake CMakeLists.txt -B conf/ -D LIBRARY_TYPE=SHARED -D BUILD_MODE=DEBUG -D MNIST_STATIC_CLASS=ON -D C++_STATIC_LIB=ON

The name of the output library will be: libmnist_reader-csl-stc-d.so

Include the mnist_reader.hpp header in your source code.

Pass the created library to your compiler.

(example for a g++)

g++ my_source_file.cpp -L path/to/lib/ -lmnist_reader

3. In your code

As you can see, mnist_reader comes in differents flavours. The basic mnist_reader configuration allows you to call :

MnistReader reader(path_to_training_dataset,path_to_training_labels,path_to_test_dataset,path_to_test_labels,true);
reader.getData(n_data,n_pixel);

Where the MNIST_STATIC_CLASS option will build the library as a static class:

MnistReader::setPathToTrainingDataset(path_to_training_dataset);
MnistReader::setPathToTestDataset(path_to_test_dataset);
MnistReader::setPathToTrainingLabels(path_to_training_labels);
MnistReader::setPathToTestLabels(path_to_test_labels);
MnistReader::load();
MnistReader::getData(n_data,n_pixel);

To get the n_pixel pixel of the n_data data of the database.

the MNIST_SUPER_CLASS option will allows you to fully inherit from the MnistReader class.

You can see other examples of use in the examples section.

Notes

Since the bytes in the Mnist database are writen in big endian, the mnist_reader library use an endianess.hpp file to convert the database in little endian.

Contact

If you find any bugs or issues using this code, please feel free to send me an email at : quentinp.dev@gmail.com

Licence

GNU GENERAL PUBLIC LICENSE

Version 3, 29 June 2007

This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See theGNU General Public License for more details.