added MNIST dataset loader

modules/datasetstools/doc/datasetstools.rst

@@ -6,8 +6,6 @@ datasetstools. Tools for working with different datasets.
 
 The datasetstools module includes classes for working with different datasets.
 
-First version of this module was implemented for **Fall2014 OpenCV Challenge**.
-
 Action Recognition
 ------------------
 
@@ -241,6 +239,22 @@ Currently implemented loading full list with urls. Planned to implement dataset
 
  3. To load data run: ./opencv/build/bin/example_datasetstools_or_imagenet -p=/home/user/path_to_unpacked_file/
 
+OR_mnist
+===========
+.. ocv:class:: OR_mnist
+
+Implements loading dataset:
+
+_`"MNIST"`: http://yann.lecun.com/exdb/mnist/
+
+.. note:: Usage
+
+ 1. From link above download dataset files: t10k-images-idx3-ubyte.gz, t10k-labels-idx1-ubyte.gz, train-images-idx3-ubyte.gz, train-labels-idx1-ubyte.gz.
+
+ 2. Unpack them.
+
+ 3. To load data run: ./opencv/build/bin/example_datasetstools_or_mnist -p=/home/user/path_to_unpacked_files/
+
 OR_sun
 ======
 .. ocv:class:: OR_sun

modules/datasetstools/include/opencv2/datasetstools/or_mnist.hpp

+/*M///////////////////////////////////////////////////////////////////////////////////////
+//
+//  IMPORTANT: READ BEFORE DOWNLOADING, COPYING, INSTALLING OR USING.
+//
+//  By downloading, copying, installing or using the software you agree to this license.
+//  If you do not agree to this license, do not download, install,
+//  copy or use the software.
+//
+//
+//                           License Agreement
+//                For Open Source Computer Vision Library
+//
+// Copyright (C) 2014, Itseez Inc, all rights reserved.
+// Third party copyrights are property of their respective owners.
+//
+// Redistribution and use in source and binary forms, with or without modification,
+// are permitted provided that the following conditions are met:
+//
+//   * Redistribution's of source code must retain the above copyright notice,
+//     this list of conditions and the following disclaimer.
+//
+//   * Redistribution's in binary form must reproduce the above copyright notice,
+//     this list of conditions and the following disclaimer in the documentation
+//     and/or other materials provided with the distribution.
+//
+//   * The name of the copyright holders may not be used to endorse or promote products
+//     derived from this software without specific prior written permission.
+//
+// This software is provided by the copyright holders and contributors "as is" and
+// any express or implied warranties, including, but not limited to, the implied
+// warranties of merchantability and fitness for a particular purpose are disclaimed.
+// In no event shall the Itseez Inc or contributors be liable for any direct,
+// indirect, incidental, special, exemplary, or consequential damages
+// (including, but not limited to, procurement of substitute goods or services;
+// loss of use, data, or profits; or business interruption) however caused
+// and on any theory of liability, whether in contract, strict liability,
+// or tort (including negligence or otherwise) arising in any way out of
+// the use of this software, even if advised of the possibility of such damage.
+//
+//M*/
+
+#ifndef OPENCV_DATASETSTOOLS_OR_MNIST_HPP
+#define OPENCV_DATASETSTOOLS_OR_MNIST_HPP
+
+#include <string>
+#include <vector>
+
+#include "opencv2/datasetstools/dataset.hpp"
+
+#include <opencv2/core.hpp>
+
+namespace cv
+{
+namespace datasetstools
+{
+
+struct OR_mnistObj : public Object
+{
+    char label; // 0..9
+    Mat image; // [28][28]
+};
+
+class CV_EXPORTS OR_mnist : public Dataset
+{
+public:
+    virtual void load(const std::string &path) = 0;
+
+    static Ptr<OR_mnist> create();
+};
+
+}
+}
+
+#endif

modules/datasetstools/samples/or_mnist.cpp

+/*M///////////////////////////////////////////////////////////////////////////////////////
+//
+//  IMPORTANT: READ BEFORE DOWNLOADING, COPYING, INSTALLING OR USING.
+//
+//  By downloading, copying, installing or using the software you agree to this license.
+//  If you do not agree to this license, do not download, install,
+//  copy or use the software.
+//
+//
+//                           License Agreement
+//                For Open Source Computer Vision Library
+//
+// Copyright (C) 2014, Itseez Inc, all rights reserved.
+// Third party copyrights are property of their respective owners.
+//
+// Redistribution and use in source and binary forms, with or without modification,
+// are permitted provided that the following conditions are met:
+//
+//   * Redistribution's of source code must retain the above copyright notice,
+//     this list of conditions and the following disclaimer.
+//
+//   * Redistribution's in binary form must reproduce the above copyright notice,
+//     this list of conditions and the following disclaimer in the documentation
+//     and/or other materials provided with the distribution.
+//
+//   * The name of the copyright holders may not be used to endorse or promote products
+//     derived from this software without specific prior written permission.
+//
+// This software is provided by the copyright holders and contributors "as is" and
+// any express or implied warranties, including, but not limited to, the implied
+// warranties of merchantability and fitness for a particular purpose are disclaimed.
+// In no event shall the Itseez Inc or contributors be liable for any direct,
+// indirect, incidental, special, exemplary, or consequential damages
+// (including, but not limited to, procurement of substitute goods or services;
+// loss of use, data, or profits; or business interruption) however caused
+// and on any theory of liability, whether in contract, strict liability,
+// or tort (including negligence or otherwise) arising in any way out of
+// the use of this software, even if advised of the possibility of such damage.
+//
+//M*/
+
+#include "opencv2/datasetstools/or_mnist.hpp"
+
+#include <opencv2/core.hpp>
+#include <opencv2/imgcodecs.hpp>
+
+#include <cstdio>
+
+#include <string>
+#include <vector>
+
+using namespace std;
+using namespace cv;
+using namespace cv::datasetstools;
+
+int main(int argc, char *argv[])
+{
+    const char *keys =
+            "{ help h usage ? |    | show this message }"
+            "{ path p         |true| path to dataset (SUN397 folder) }";
+    CommandLineParser parser(argc, argv, keys);
+    string path(parser.get<string>("path"));
+    if (parser.has("help") || path=="true")
+    {
+        parser.printMessage();
+        return -1;
+    }
+
+    Ptr<OR_mnist> dataset = OR_mnist::create();
+    dataset->load(path);
+
+    // ***************
+    // dataset contains for each object its image and label.
+    // For example, let output train & test sizes and their first elements.
+    printf("train size: %u\n", (unsigned int)dataset->getTrain().size());
+    printf("test size: %u\n", (unsigned int)dataset->getTest().size());
+
+    OR_mnistObj *example = static_cast<OR_mnistObj *>(dataset->getTrain()[0].get());
+    printf("first train:\nlabel: %u\n", example->label);
+    printf("image was saved to train0.png\n");
+    imwrite("train0.png", example->image);
+
+    example = static_cast<OR_mnistObj *>(dataset->getTest()[0].get());
+    printf("first test:\nlabel: %u\n", example->label);
+    printf("image was saved to test0.png\n");
+    imwrite("test0.png", example->image);
+
+    return 0;
+}

modules/datasetstools/src/or_mnist.cpp

+/*M///////////////////////////////////////////////////////////////////////////////////////
+//
+//  IMPORTANT: READ BEFORE DOWNLOADING, COPYING, INSTALLING OR USING.
+//
+//  By downloading, copying, installing or using the software you agree to this license.
+//  If you do not agree to this license, do not download, install,
+//  copy or use the software.
+//
+//
+//                           License Agreement
+//                For Open Source Computer Vision Library
+//
+// Copyright (C) 2014, Itseez Inc, all rights reserved.
+// Third party copyrights are property of their respective owners.
+//
+// Redistribution and use in source and binary forms, with or without modification,
+// are permitted provided that the following conditions are met:
+//
+//   * Redistribution's of source code must retain the above copyright notice,
+//     this list of conditions and the following disclaimer.
+//
+//   * Redistribution's in binary form must reproduce the above copyright notice,
+//     this list of conditions and the following disclaimer in the documentation
+//     and/or other materials provided with the distribution.
+//
+//   * The name of the copyright holders may not be used to endorse or promote products
+//     derived from this software without specific prior written permission.
+//
+// This software is provided by the copyright holders and contributors "as is" and
+// any express or implied warranties, including, but not limited to, the implied
+// warranties of merchantability and fitness for a particular purpose are disclaimed.
+// In no event shall the Itseez Inc or contributors be liable for any direct,
+// indirect, incidental, special, exemplary, or consequential damages
+// (including, but not limited to, procurement of substitute goods or services;
+// loss of use, data, or profits; or business interruption) however caused
+// and on any theory of liability, whether in contract, strict liability,
+// or tort (including negligence or otherwise) arising in any way out of
+// the use of this software, even if advised of the possibility of such damage.
+//
+//M*/
+
+#include "opencv2/datasetstools/or_mnist.hpp"
+#include "precomp.hpp"
+
+namespace cv
+{
+namespace datasetstools
+{
+
+using namespace std;
+
+class CV_EXPORTS OR_mnistImp : public OR_mnist
+{
+public:
+    OR_mnistImp() {}
+    //OR_mnistImp(const string &path);
+    virtual ~OR_mnistImp() {}
+
+    virtual void load(const string &path);
+
+private:
+    void loadDataset(const string &path);
+
+    void loadDatasetPart(const string &imagesFile, const string &labelsFile, unsigned int num, vector< Ptr<Object> > &dataset_);
+};
+
+/*OR_mnistImp::OR_mnistImp(const string &path)
+{
+    loadDataset(path);
+}*/
+
+void OR_mnistImp::load(const string &path)
+{
+    loadDataset(path);
+}
+
+void OR_mnistImp::loadDatasetPart(const string &imagesFile, const string &labelsFile, unsigned int num, vector< Ptr<Object> > &dataset_)
+{
+    FILE *f = fopen(imagesFile.c_str(), "rb");
+    fseek(f, 16, SEEK_CUR);
+    unsigned int imageSize = 28*28;
+    char *images = new char[num*imageSize];
+    size_t res = fread(images, 1, num*imageSize, f);
+    fclose(f);
+    if (num*imageSize != res)
+    {
+        return;
+    }
+    f = fopen(labelsFile.c_str(), "rb");
+    fseek(f, 8, SEEK_CUR);
+    char *labels = new char[num];
+    res = fread(labels, 1, num, f);
+    fclose(f);
+    if (num != res)
+    {
+        return;
+    }
+
+    for (unsigned int i=0; i<num; ++i)
+    {
+        Ptr<OR_mnistObj> curr(new OR_mnistObj);
+        curr->label = labels[i];
+
+        curr->image = Mat(28, 28, CV_8U);
+        unsigned int imageIdx = i*imageSize;
+        for (int j=0; j<curr->image.rows; ++j)
+        {
+            char *im = curr->image.ptr<char>(j);
+            for (int k=0; k<curr->image.cols; ++k)
+            {
+                im[k] = images[imageIdx + j*28 + k];
+            }
+        }
+
+        dataset_.push_back(curr);
+    }
+    delete[] images;
+    delete[] labels;
+}
+
+void OR_mnistImp::loadDataset(const string &path)
+{
+    train.push_back(vector< Ptr<Object> >());
+    test.push_back(vector< Ptr<Object> >());
+    validation.push_back(vector< Ptr<Object> >());
+
+    string trainImagesFile(path + "train-images.idx3-ubyte");
+    string trainLabelsFile(path + "train-labels.idx1-ubyte");
+    loadDatasetPart(trainImagesFile, trainLabelsFile, 60000, train.back());
+
+    string testImagesFile(path + "t10k-images.idx3-ubyte");
+    string testLabelsFile(path + "t10k-labels.idx1-ubyte");
+    loadDatasetPart(testImagesFile, testLabelsFile, 10000, test.back());
+}
+
+Ptr<OR_mnist> OR_mnist::create()
+{
+    return Ptr<OR_mnistImp>(new OR_mnistImp);
+}
+
+}
+}