COMPMID-344 Updated doxygen

Change-Id: I32f7b84daa560e460b77216add529c8fa8b327ae
diff --git a/utils/Utils.h b/utils/Utils.h
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+/*
+ * Copyright (c) 2016, 2017 ARM Limited.
+ *
+ * SPDX-License-Identifier: MIT
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to
+ * deal in the Software without restriction, including without limitation the
+ * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+ * sell copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+#ifndef __UTILS_UTILS_H__
+#define __UTILS_UTILS_H__
+
+#include "arm_compute/core/Helpers.h"
+#include "arm_compute/core/ITensor.h"
+#include "arm_compute/core/Types.h"
+#include "arm_compute/core/Validate.h"
+#include "arm_compute/runtime/Tensor.h"
+
+#ifdef ARM_COMPUTE_CL
+#include "arm_compute/core/CL/OpenCL.h"
+#include "arm_compute/runtime/CL/CLTensor.h"
+#endif /* ARM_COMPUTE_CL */
+
+#include <cstdlib>
+#include <cstring>
+#include <fstream>
+#include <iostream>
+
+namespace arm_compute
+{
+namespace utils
+{
+/** Signature of an example to run
+ *
+ * @param[in] argc Number of command line arguments
+ * @param[in] argv Command line arguments
+ */
+using example = void(int argc, const char **argv);
+
+/** Run an example and handle the potential exceptions it throws
+ *
+ * @param[in] argc Number of command line arguments
+ * @param[in] argv Command line arguments
+ * @param[in] func Pointer to the function containing the code to run
+ */
+int run_example(int argc, const char **argv, example &func);
+
+/** Draw a RGB rectangular window for the detected object
+ *
+ * @param[in, out] tensor Input tensor where the rectangle will be drawn on. Format supported: RGB888
+ * @param[in]      rect   Geometry of the rectangular window
+ * @param[in]      r      Red colour to use
+ * @param[in]      g      Green colour to use
+ * @param[in]      b      Blue colour to use
+ */
+void draw_detection_rectangle(arm_compute::ITensor *tensor, const arm_compute::DetectionWindow &rect, uint8_t r, uint8_t g, uint8_t b);
+
+/** Parse the ppm header from an input file stream. At the end of the execution,
+ *  the file position pointer will be located at the first pixel stored in the ppm file
+ *
+ * @param[in] fs Input file stream to parse
+ *
+ * @return The width, height and max value stored in the header of the PPM file
+ */
+std::tuple<unsigned int, unsigned int, int> parse_ppm_header(std::ifstream &fs);
+
+/** Class to load the content of a PPM file into an Image
+ */
+class PPMLoader
+{
+public:
+    PPMLoader()
+        : _fs(), _width(0), _height(0)
+    {
+    }
+    /** Open a PPM file and reads its metadata (Width, height)
+     *
+     * @param[in] ppm_filename File to open
+     */
+    void open(const std::string &ppm_filename)
+    {
+        ARM_COMPUTE_ERROR_ON(is_open());
+        try
+        {
+            _fs.exceptions(std::ifstream::failbit | std::ifstream::badbit);
+            _fs.open(ppm_filename, std::ios::in | std::ios::binary);
+
+            unsigned int max_val = 0;
+            std::tie(_width, _height, max_val) = parse_ppm_header(_fs);
+
+            ARM_COMPUTE_ERROR_ON_MSG(max_val >= 256, "2 bytes per colour channel not supported in file %s", ppm_filename.c_str());
+        }
+        catch(const std::ifstream::failure &e)
+        {
+            ARM_COMPUTE_ERROR("Accessing %s: %s", ppm_filename.c_str(), e.what());
+        }
+    }
+    /** Return true if a PPM file is currently open
+         */
+    bool is_open()
+    {
+        return _fs.is_open();
+    }
+
+    /** Initialise an image's metadata with the dimensions of the PPM file currently open
+     *
+     * @param[out] image  Image to initialise
+     * @param[in]  format Format to use for the image (Must be RGB888 or U8)
+     */
+    template <typename T>
+    void init_image(T &image, arm_compute::Format format)
+    {
+        ARM_COMPUTE_ERROR_ON(!is_open());
+        ARM_COMPUTE_ERROR_ON(format != arm_compute::Format::RGB888 && format != arm_compute::Format::U8);
+
+        // Use the size of the input PPM image
+        arm_compute::TensorInfo image_info(_width, _height, format);
+        image.allocator()->init(image_info);
+    }
+
+    /** Fill an image with the content of the currently open PPM file.
+     *
+     * @note If the image is a CLImage, the function maps and unmaps the image
+     *
+     * @param[in,out] image Image to fill (Must be allocated, and of matching dimensions with the opened PPM).
+     */
+    template <typename T>
+    void fill_image(T &image)
+    {
+        ARM_COMPUTE_ERROR_ON(!is_open());
+        ARM_COMPUTE_ERROR_ON(image.info()->dimension(0) != _width || image.info()->dimension(1) != _height);
+        ARM_COMPUTE_ERROR_ON_FORMAT_NOT_IN(&image, arm_compute::Format::U8, arm_compute::Format::RGB888);
+        try
+        {
+#ifdef ARM_COMPUTE_CL
+            // Map buffer if creating a CLTensor
+            if(std::is_same<typename std::decay<T>::type, arm_compute::CLImage>::value)
+            {
+                image.map();
+            }
+#endif
+            // Check if the file is large enough to fill the image
+            const size_t current_position = _fs.tellg();
+            _fs.seekg(0, std::ios_base::end);
+            const size_t end_position = _fs.tellg();
+            _fs.seekg(current_position, std::ios_base::beg);
+
+            ARM_COMPUTE_ERROR_ON_MSG((end_position - current_position) < image.info()->tensor_shape().total_size() * image.info()->element_size(),
+                                     "Not enough data in file");
+            ARM_COMPUTE_UNUSED(end_position);
+
+            switch(image.info()->format())
+            {
+                case arm_compute::Format::U8:
+                {
+                    // We need to convert the data from RGB to grayscale:
+                    // Iterate through every pixel of the image
+                    arm_compute::Window window;
+                    window.set(arm_compute::Window::DimX, arm_compute::Window::Dimension(0, _width, 1));
+                    window.set(arm_compute::Window::DimY, arm_compute::Window::Dimension(0, _height, 1));
+
+                    arm_compute::Iterator out(&image, window);
+
+                    unsigned char red   = 0;
+                    unsigned char green = 0;
+                    unsigned char blue  = 0;
+
+                    arm_compute::execute_window_loop(window, [&](const arm_compute::Coordinates & id)
+                    {
+                        red   = _fs.get();
+                        green = _fs.get();
+                        blue  = _fs.get();
+
+                        *out.ptr() = 0.2126f * red + 0.7152f * green + 0.0722f * blue;
+                    },
+                    out);
+
+                    break;
+                }
+                case arm_compute::Format::RGB888:
+                {
+                    // There is no format conversion needed: we can simply copy the content of the input file to the image one row at the time.
+                    // Create a vertical window to iterate through the image's rows:
+                    arm_compute::Window window;
+                    window.set(arm_compute::Window::DimY, arm_compute::Window::Dimension(0, _height, 1));
+
+                    arm_compute::Iterator out(&image, window);
+
+                    arm_compute::execute_window_loop(window, [&](const arm_compute::Coordinates & id)
+                    {
+                        // Copy one row from the input file to the current row of the image:
+                        _fs.read(reinterpret_cast<std::fstream::char_type *>(out.ptr()), _width * image.info()->element_size());
+                    },
+                    out);
+
+                    break;
+                }
+                default:
+                    ARM_COMPUTE_ERROR("Unsupported format");
+            }
+
+#ifdef ARM_COMPUTE_CL
+            // Unmap buffer if creating a CLTensor
+            if(std::is_same<typename std::decay<T>::type, arm_compute::CLTensor>::value)
+            {
+                image.unmap();
+            }
+#endif
+        }
+        catch(const std::ifstream::failure &e)
+        {
+            ARM_COMPUTE_ERROR("Loading PPM file: %s", e.what());
+        }
+    }
+
+private:
+    std::ifstream _fs;
+    unsigned int  _width, _height;
+};
+
+/** Template helper function to save a tensor image to a PPM file.
+ *
+ * @note Only U8 and RGB888 formats supported.
+ * @note Only works with 2D tensors.
+ * @note If the input tensor is a CLTensor, the function maps and unmaps the image
+ *
+ * @param[in] tensor       The tensor to save as PPM file
+ * @param[in] ppm_filename Filename of the file to create.
+ */
+template <typename T>
+void save_to_ppm(T &tensor, const std::string &ppm_filename)
+{
+    ARM_COMPUTE_ERROR_ON_FORMAT_NOT_IN(&tensor, arm_compute::Format::RGB888, arm_compute::Format::U8);
+    ARM_COMPUTE_ERROR_ON(tensor.info()->num_dimensions() > 2);
+
+    std::ofstream fs;
+
+    try
+    {
+        fs.exceptions(std::ofstream::failbit | std::ofstream::badbit | std::ofstream::eofbit);
+        fs.open(ppm_filename, std::ios::out | std::ios::binary);
+
+        const unsigned int width  = tensor.info()->tensor_shape()[0];
+        const unsigned int height = tensor.info()->tensor_shape()[1];
+
+        fs << "P6\n"
+           << width << " " << height << " 255\n";
+
+#ifdef ARM_COMPUTE_CL
+        // Map buffer if creating a CLTensor
+        if(std::is_same<typename std::decay<T>::type, arm_compute::CLTensor>::value)
+        {
+            tensor.map();
+        }
+#endif
+
+        switch(tensor.info()->format())
+        {
+            case arm_compute::Format::U8:
+            {
+                arm_compute::Window window;
+                window.set(arm_compute::Window::DimX, arm_compute::Window::Dimension(0, width, 1));
+                window.set(arm_compute::Window::DimY, arm_compute::Window::Dimension(0, height, 1));
+
+                arm_compute::Iterator in(&tensor, window);
+
+                arm_compute::execute_window_loop(window, [&](const arm_compute::Coordinates & id)
+                {
+                    const unsigned char value = *in.ptr();
+
+                    fs << value << value << value;
+                },
+                in);
+
+                break;
+            }
+            case arm_compute::Format::RGB888:
+            {
+                arm_compute::Window window;
+                window.set(arm_compute::Window::DimX, arm_compute::Window::Dimension(0, width, width));
+                window.set(arm_compute::Window::DimY, arm_compute::Window::Dimension(0, height, 1));
+
+                arm_compute::Iterator in(&tensor, window);
+
+                arm_compute::execute_window_loop(window, [&](const arm_compute::Coordinates & id)
+                {
+                    fs.write(reinterpret_cast<std::fstream::char_type *>(in.ptr()), width * tensor.info()->element_size());
+                },
+                in);
+
+                break;
+            }
+            default:
+                ARM_COMPUTE_ERROR("Unsupported format");
+        }
+#ifdef ARM_COMPUTE_CL
+        // Unmap buffer if creating a CLTensor
+        if(std::is_same<typename std::decay<T>::type, arm_compute::CLTensor>::value)
+        {
+            tensor.unmap();
+        }
+#endif
+    }
+    catch(const std::ofstream::failure &e)
+    {
+        ARM_COMPUTE_ERROR("Writing %s: (%s)", ppm_filename.c_str(), e.what());
+    }
+}
+} // namespace utils
+} // namespace arm_compute
+#endif /* __UTILS_UTILS_H__*/