ImageFile.cpp

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/*
 * SPDX-FileCopyrightText: 2006-2021 Istituto Italiano di Tecnologia (IIT)
 * SPDX-FileCopyrightText: 2006-2010 RobotCub Consortium
 * SPDX-License-Identifier: BSD-3-Clause
 */
 
#include <yarp/sig/ImageFile.h>
#include <yarp/os/LogComponent.h>
#include <yarp/os/LogStream.h>
 
#include <cstdio>
#include <cstring>
#include <cstdlib>
 
#if defined (YARP_HAS_JPEG)
#include "jpeglib.h"
#endif
 
#if defined (YARP_HAS_PNG)
#include <png.h>
#endif
 
#if defined (YARP_HAS_ZLIB)
#include <zlib.h>
#endif
 
using namespace yarp::os;
using namespace yarp::sig;
 
namespace
{
    YARP_LOG_COMPONENT(IMAGEFILE, "yarp.sig.ImageFile")
}
 
namespace
{
    bool ImageReadRGB_JPG(ImageOf<PixelRgb>& img, const char* filename);
    bool ImageReadBGR_JPG(ImageOf<PixelBgr>& img, const char* filename);
    bool ImageReadMono_JPG(ImageOf<PixelMono>& img, const char* filename);
 
    bool ImageReadRGB_PNG(ImageOf<PixelRgb>& img, const char* filename);
    bool ImageReadBGR_PNG(ImageOf<PixelBgr>& img, const char* filename);
    bool ImageReadMono_PNG(ImageOf<PixelMono>& img, const char* filename);
 
    bool ReadHeader_PxM(FILE* fp, int* height, int* width, int* color);
    bool ImageReadMono_PxM(ImageOf<PixelMono>& img, const char* filename);
    bool ImageReadRGB_PxM(ImageOf<PixelRgb>& img, const char* filename);
    bool ImageReadBGR_PxM(ImageOf<PixelBgr>& img, const char* filename);
 
    bool ImageReadFloat_PlainHeaderless(ImageOf<PixelFloat>& dest, const std::string& filename);
#if defined (YARP_HAS_ZLIB)
    bool ImageReadFloat_CompressedHeaderless(ImageOf<PixelFloat>& dest, const std::string& filename);
#endif
 
    bool SaveJPG(char* src, const char* filename, size_t h, size_t w, size_t rowSize);
    bool SavePGM(char* src, const char* filename, size_t h, size_t w, size_t rowSize);
    bool SavePPM(char* src, const char* filename, size_t h, size_t w, size_t rowSize);
#if defined (YARP_HAS_PNG)
    bool SavePNG(char* src, const char* filename, size_t h, size_t w, size_t rowSize, png_byte color_type, png_byte bit_depth);
#endif
    bool SaveFloatRaw(char* src, const char* filename, size_t h, size_t w, size_t rowSize);
#if defined (YARP_HAS_ZLIB)
    bool SaveFloatCompressed(char* src, const char* filename, size_t h, size_t w, size_t rowSize);
#endif
 
    bool ImageWriteJPG(ImageOf<PixelRgb>& img, const char* filename);
    bool ImageWritePNG(ImageOf<PixelRgb>& img, const char* filename);
    bool ImageWritePNG(ImageOf<PixelMono>& img, const char* filename);
    bool ImageWriteRGB(ImageOf<PixelRgb>& img, const char* filename);
    bool ImageWriteMono(ImageOf<PixelMono>& img, const char* filename);
 
    bool ImageWriteFloat_PlainHeaderless(ImageOf<PixelFloat>& img, const char* filename);
    bool ImageWriteFloat_CompressedHeaderless(ImageOf<PixelFloat>& img, const char* filename);
};
 
// private read methods for JPG Files
namespace {
bool ImageReadRGB_JPG(ImageOf<PixelRgb>& img, const char* filename)
{
#if defined (YARP_HAS_JPEG)
 
    struct jpeg_decompress_struct cinfo;
    struct jpeg_error_mgr jerr;
    jpeg_create_decompress(&cinfo);
    cinfo.err = jpeg_std_error(&jerr);
 
    FILE* fp = fopen(filename, "rb");
    if (fp == NULL)
    {
        yCError(IMAGEFILE) << "Error: failed to open" << filename;
        return false;
    }
 
    jpeg_stdio_src(&cinfo, fp);
    jpeg_read_header(&cinfo, TRUE);
    jpeg_start_decompress(&cinfo);
 
    uint32_t j_width = cinfo.image_width;
    uint32_t j_height = cinfo.image_height;
    uint32_t j_ch = cinfo.num_components;
 
    uint8_t* j_data = NULL;
    j_data = (uint8_t*)malloc(sizeof(uint8_t) * j_width * j_height * j_ch);
 
    //read line by line
    uint8_t* j_row = j_data;
    const uint32_t j_stride = j_width * j_ch;
    for (size_t y = 0; y < j_height; y++)
    {
        jpeg_read_scanlines(&cinfo, &j_row, 1);
        j_row += j_stride;
    }
 
    jpeg_finish_decompress(&cinfo);
    jpeg_destroy_decompress(&cinfo);
    fclose(fp);
 
    img.resize(j_width, j_height);
    for (size_t y = 0; y < j_height; y++)
    {
        for (size_t x = 0; x < j_width; x++)
        {
            unsigned char* address = img.getPixelAddress(x, y);
            address[0] = j_data[y * j_width * j_ch + x * j_ch + 0];
            address[1] = j_data[y * j_width * j_ch + x * j_ch + 1];
            address[2] = j_data[y * j_width * j_ch + x * j_ch + 2];
        }
    }
 
    free(j_data);
    j_data = nullptr;
 
    return true;
#else
    yCError(IMAGEFILE) << "JPG library not available/not found";
    return false;
#endif
}
 
bool ImageReadBGR_JPG(ImageOf<PixelBgr>& img, const char* filename)
{
#if defined (YARP_HAS_JPEG)
    yCError(IMAGEFILE) << "Not yet implemented";
    return false;
#else
    yCError(IMAGEFILE) << "JPG library not available/not found";
    return false;
#endif
}
 
bool ImageReadMono_JPG(ImageOf<PixelMono>& img, const char* filename)
{
#if defined (YARP_HAS_JPEG)
    yCError(IMAGEFILE) << "Not yet implemented";
    return false;
#else
    yCError(IMAGEFILE) << "JPG library not available/not found";
    return false;
#endif
}
}
 
// private read methods for PNG Files
namespace {
bool ImageReadRGB_PNG(ImageOf<PixelRgb>& img, const char* filename)
{
#if defined (YARP_HAS_PNG)
    FILE* fp = fopen(filename, "rb");
 
    png_structp png = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
    if (!png)
    {
        yCError(IMAGEFILE) << "PNG internal error";
        return false;
    }
 
    png_infop info = png_create_info_struct(png);
    if (!info)
    {
        yCError(IMAGEFILE) << "PNG internal error";
        return false;
    }
 
    if (setjmp(png_jmpbuf(png)))
    {
        yCError(IMAGEFILE) << "PNG internal error";
        return false;
    }
 
    png_init_io(png, fp);
 
    png_read_info(png, info);
 
    int width = png_get_image_width(png, info);
    int height = png_get_image_height(png, info);
    png_byte color_type = png_get_color_type(png, info);
    png_byte bit_depth = png_get_bit_depth(png, info);
 
    // Read any color_type into 8bit depth, RGBA format.
    // See http://www.libpng.org/pub/png/libpng-manual.txt
 
    if (bit_depth == 16) {
        png_set_strip_16(png);
    }
 
    if (color_type == PNG_COLOR_TYPE_PALETTE) {
        png_set_palette_to_rgb(png);
    }
 
    // PNG_COLOR_TYPE_GRAY_ALPHA is always 8 or 16bit depth.
    if (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8) {
        png_set_expand_gray_1_2_4_to_8(png);
    }
 
    if (png_get_valid(png, info, PNG_INFO_tRNS)) {
        png_set_tRNS_to_alpha(png);
    }
 
    // These color_type don't have an alpha channel then fill it with 0xff.
    if (color_type == PNG_COLOR_TYPE_RGB || color_type == PNG_COLOR_TYPE_GRAY || color_type == PNG_COLOR_TYPE_PALETTE) {
        png_set_filler(png, 0xFF, PNG_FILLER_AFTER);
    }
 
    if (color_type == PNG_COLOR_TYPE_GRAY || color_type == PNG_COLOR_TYPE_GRAY_ALPHA) {
        png_set_gray_to_rgb(png);
    }
 
    png_read_update_info(png, info);
 
    png_bytep* row_pointers = (png_bytep*)malloc(sizeof(png_bytep) * height);
    for (int y = 0; y < height; y++)
    {
        row_pointers[y] = (png_byte*)malloc(png_get_rowbytes(png, info));
    }
 
    png_read_image(png, row_pointers);
    fclose(fp);
 
    img.resize(width,height);
    for (int y = 0; y < height; y++)
    {
        png_bytep row = row_pointers[y];
        for (int x = 0; x < width; x++)
            {
                png_bytep px = &(row[x * 4]);
                unsigned char* address = img.getPixelAddress(x,y);
                address[0] = px[0];
                address[1] = px[1];
                address[2] = px[2];
            }
    }
 
    png_destroy_read_struct(&png, &info, NULL);
    for (int y = 0; y < height; y++)
    {
        free(row_pointers[y]);
    }
    free(row_pointers);
    return true;
#else
    yCError(IMAGEFILE) << "PNG library not available/not found";
    return false;
#endif
}
 
bool ImageReadBGR_PNG(ImageOf<PixelBgr>& img, const char* filename)
{
#if defined (YARP_HAS_PNG)
    yCError(IMAGEFILE) << "Not yet implemented";
    return false;
#else
    yCError(IMAGEFILE) << "PNG library not available/not found";
    return false;
#endif
}
 
bool ImageReadMono_PNG(ImageOf<PixelMono>& img, const char* filename)
{
#if defined (YARP_HAS_PNG)
    yCError(IMAGEFILE) << "Not yet implemented";
    return false;
#else
    yCError(IMAGEFILE) << "PNG library not available/not found";
    return false;
#endif
}
 
// private read methods for PGM/PPM Files
 
bool ReadHeader_PxM(FILE *fp, int *height, int *width, int *color)
{
    char ch;
    int  maxval;
 
    *color = 0;
 
    if (fscanf(fp, "P%c\n", &ch) != 1 || (ch!='6'&&ch!='5'))
    {
        yCWarning(IMAGEFILE, "file is not in pgm/ppm raw format; cannot read");
        return false;
    }
 
    if (ch == '6') {
        *color = 1;
    }
 
    // skip comments
    ch = fgetc(fp);
    while (ch == '#')
    {
        do
        {
            ch = fgetc(fp);
        }
        while (ch != '\n');
        ch = fgetc(fp);
    }
    ungetc(ch, fp);
 
    int n=fscanf(fp, "%d%d%d", width, height, &maxval);
    if (n != 3) {
        return false;
    }
 
    fgetc(fp);
    if (maxval != 255)
    {
        //die("image is not true-color (24 bit); read failed");
        yCWarning(IMAGEFILE, "image is not true-color (24 bit); read failed");
        return false;
    }
 
    return true;
}
 
 
bool ImageReadRGB_PxM(ImageOf<PixelRgb> &img, const char *filename)
{
    int width, height, color, num;
    FILE *fp=nullptr;
    fp = fopen(filename, "rb");
 
    if(fp==nullptr)
    {
        yCError(IMAGEFILE, "Error opening %s, check if file exists.\n", filename);
        return false;
    }
 
    if (!ReadHeader_PxM(fp, &height, &width, &color))
    {
        fclose (fp);
        yCError(IMAGEFILE, "Error reading header, is file a valid ppm/pgm?\n");
        return false;
    }
 
    if (!color)
    {
        ImageOf<PixelMono> tmp;
        tmp.resize(width,height);
 
        const int w = tmp.width() * tmp.getPixelSize();
        const int h = tmp.height();
        const int pad = tmp.getRowSize();
        unsigned char *dst = tmp.getRawImage ();
 
        num = 0;
        for (int i = 0; i < h; i++)
            {
                num += (int)fread((void *) dst, 1, (size_t) w, fp);
                dst += pad;
            }
        fclose(fp);
        img.copy(tmp);
        return true;
    }
 
    img.resize(width,height);
 
    const int w = img.width() * img.getPixelSize();
    const int h = img.height();
    const int pad = img.getRowSize();
    unsigned char *dst = img.getRawImage ();
 
    num = 0;
    for (int i = 0; i < h; i++)
    {
        num += (int)fread((void *) dst, 1, (size_t) w, fp);
        dst += pad;
    }
 
    fclose(fp);
 
    return true;
}
 
#if defined (YARP_HAS_ZLIB)
bool ImageReadFloat_CompressedHeaderless(ImageOf<PixelFloat>& dest, const std::string& filename)
{
    FILE* fp = fopen(filename.c_str(), "rb");
    if (fp == nullptr) {
        return false;
    }
 
    size_t br = 0;
 
    //get the file size
    fseek(fp, 0, SEEK_END);
    size_t sizeDataCompressed = ftell(fp);
    rewind(fp);
 
    //read the compressed data
    char* dataReadInCompressed = new char[sizeDataCompressed];
    br = fread(dataReadInCompressed, 1, sizeDataCompressed, fp);
    fclose(fp);
 
    if (br != sizeDataCompressed) { yError() << "problems reading file!"; delete [] dataReadInCompressed; return false; }
 
    size_t h = ((size_t*)(dataReadInCompressed))[0]; //byte 0
    size_t w = ((size_t*)(dataReadInCompressed))[1]; //byte 8, because size_t is 8 bytes long
    size_t hds = 2* sizeof(size_t); //16 bytes
 
    dest.resize(w, h);
    unsigned char* destbuff = dest.getRawImage();
    //this is the size of the image
    size_t sizeDataUncompressed = dest.getRawImageSize();
    //this is the size of the buffer. Extra space is required for temporary operations (I choose arbitrarily *2)
    size_t sizeDataUncompressedExtra = sizeDataUncompressed*2;
 
    char* dataUncompressed = new char[sizeDataUncompressedExtra];
 
    int z_result = uncompress((Bytef*) dataUncompressed, (uLongf*)&sizeDataUncompressedExtra, (const Bytef*)dataReadInCompressed+ hds, sizeDataCompressed- hds);
    switch (z_result)
    {
    case Z_OK:
        break;
 
    case Z_MEM_ERROR:
        yCError(IMAGEFILE, "zlib compression: out of memory");
        delete[] dataUncompressed;
        return false;
        break;
 
    case Z_BUF_ERROR:
        yCError(IMAGEFILE, "zlib compression: output buffer wasn't large enough");
        delete[] dataUncompressed;
        return false;
        break;
 
    case Z_DATA_ERROR:
        yCError(IMAGEFILE, "zlib compression: file contains corrupted data");
        delete[] dataUncompressed;
        return false;
        break;
    }
 
    //here I am copy only the size of the image, obviously the extra space is not needed anymore.
    for (size_t i=0; i< sizeDataUncompressed; i++)
    {
        destbuff[i] = dataUncompressed[i];
    }
 
    delete [] dataUncompressed;
    return true;
}
#endif
 
bool ImageReadFloat_PlainHeaderless(ImageOf<PixelFloat>& dest, const std::string& filename)
{
    FILE *fp = fopen(filename.c_str(), "rb");
    if (fp == nullptr) {
        return false;
    }
 
    size_t dims[2];
    if (fread(dims, sizeof(dims), 1, fp) == 0)
    {
        fclose(fp);
        return false;
    }
 
    size_t h = dims[0];
    size_t w = dims[1];
    dest.resize(w, h);
    size_t pad = dest.getRowSize();
    size_t bytes_to_read_per_row = w* dest.getPixelSize();
    unsigned char* dst = dest.getRawImage();
    size_t num = 0;
    for (size_t i = 0; i < h; i++)
    {
        num += (int)fread((void*)dst, 1, bytes_to_read_per_row, fp);
        dst += pad;
    }
 
    fclose(fp);
    return (num > 0);
}
 
bool ImageReadBGR_PxM(ImageOf<PixelBgr> &img, const char *filename)
{
    int width, height, color, num;
    FILE *fp=nullptr;
    fp = fopen(filename, "rb");
 
    if(fp==nullptr)
    {
        yCError(IMAGEFILE, "Error opening %s, check if file exists.\n", filename);
        return false;
    }
 
    if (!ReadHeader_PxM(fp, &height, &width, &color))
    {
        fclose (fp);
        yCError(IMAGEFILE, "Error reading header, is file a valid ppm/pgm?\n");
        return false;
    }
 
    if (!color)
    {
        fclose(fp);
        yCError(IMAGEFILE, "File is grayscale, conversion not yet supported\n");
        return false;
    }
 
    ImageOf<PixelRgb> tmpImg;
    tmpImg.resize(width, height);
 
    const int w = tmpImg.width() * img.getPixelSize();
    const int h = tmpImg.height();
    const int pad = tmpImg.getRowSize();
    unsigned char *dst = tmpImg.getRawImage ();
 
    num = 0;
    for (int i = 0; i < h; i++)
    {
        num += (int)fread((void *) dst, 1, (size_t) w, fp);
        dst += pad;
    }
 
    fclose(fp);
 
    return img.copy(tmpImg);
}
 
 
bool ImageReadMono_PxM(ImageOf<PixelMono> &img, const char *filename)
{
    int width, height, color, num;
    FILE *fp=nullptr;
    fp = fopen(filename, "rb");
 
    if(fp==nullptr)
    {
        yCError(IMAGEFILE, "Error opening %s, check if file exists.\n", filename);
        return false;
    }
 
    if (!ReadHeader_PxM(fp, &height, &width, &color))
    {
        fclose (fp);
        yCError(IMAGEFILE, "Error reading header, is file a valid ppm/pgm?\n");
        return false;
    }
 
    if (color)
    {
        fclose(fp);
        yCError(IMAGEFILE, "File is color, conversion not yet supported\n");
        return false;
    }
 
    img.resize(width,height);
 
    const int w = img.width() * img.getPixelSize();
    const int h = img.height();
    const int pad = img.getRowSize();
    unsigned char *dst = img.getRawImage ();
 
    num = 0;
    for (int i = 0; i < h; i++)
    {
        num += (int)fread((void *) dst, 1, (size_t) w, fp);
        dst += pad;
    }
 
    fclose(fp);
 
    return true;
}
 
// private write methods
 
#if defined (YARP_HAS_PNG)
bool SavePNG(char *src, const char *filename, size_t h, size_t w, size_t rowSize, png_byte color_type, png_byte bit_depth)
{
    // create file
    if (src == nullptr)
    {
        yCError(IMAGEFILE, "[write_png_file] Cannot write to file a nullptr image");
        return false;
    }
 
    if (filename == nullptr)
    {
        yCError(IMAGEFILE, "[write_png_file] Filename is nullptr");
        return false;
    }
 
    FILE *fp = fopen(filename, "wb");
    if (!fp)
    {
        yCError(IMAGEFILE, "[write_png_file] File %s could not be opened for writing", filename);
        return false;
    }
 
    // initialize stuff
    png_structp png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
    if (!png_ptr)
    {
        yCError(IMAGEFILE, "[write_png_file] png_create_write_struct failed");
        fclose(fp);
        return false;
    }
 
    png_infop info_ptr = png_create_info_struct(png_ptr);
    if (!info_ptr)
    {
        yCError(IMAGEFILE, "[write_png_file] png_create_info_struct failed");
        fclose(fp);
        return false;
    }
 
    //init io
    if (setjmp(png_jmpbuf(png_ptr)))
    {
        yCError(IMAGEFILE, "[write_png_file] Error during init_io");
        fclose(fp);
        return false;
    }
    png_init_io(png_ptr, fp);
 
    // write header
    if (setjmp(png_jmpbuf(png_ptr)))
    {
        yCError(IMAGEFILE, "[write_png_file] Error during writing header");
        fclose(fp);
        return false;
    }
    png_set_IHDR(png_ptr, info_ptr, w, h,
        bit_depth, color_type, PNG_INTERLACE_NONE,
        PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
 
    //write info
    png_write_info(png_ptr, info_ptr);
 
    //allocate data space
    png_bytep* row_pointers = new png_bytep[h];
 
    for (size_t y = 0; y < h; y++)
    {
        //this is an array of pointers. Each element points to a row of the image
        row_pointers[y] = (png_bytep)(src) + (y * rowSize);
    }
 
    // write bytes
    if (setjmp(png_jmpbuf(png_ptr)))
    {
        yCError(IMAGEFILE, "[write_png_file] Error during writing bytes");
        delete [] row_pointers;
        png_destroy_write_struct(&png_ptr, &info_ptr);
        fclose(fp);
        return false;
    }
    png_write_image(png_ptr, row_pointers);
 
    // end write
    if (setjmp(png_jmpbuf(png_ptr)))
    {
        yCError(IMAGEFILE, "[write_png_file] Error during end of write");
        delete [] row_pointers;
        png_destroy_write_struct(&png_ptr, &info_ptr);
        fclose(fp);
        return false;
    }
    png_write_end(png_ptr, info_ptr);
 
    // finished. cleanup  allocation
    delete[] row_pointers;
    png_destroy_write_struct(&png_ptr, &info_ptr);
    fclose(fp);
    return true;
}
#endif
 
bool SaveJPG(char *src, const char *filename, size_t h, size_t w, size_t rowSize)
{
#if defined (YARP_HAS_JPEG)
    int quality = 100;
    struct jpeg_compress_struct cinfo;
    struct jpeg_error_mgr jerr;
    FILE * outfile = nullptr;
    JSAMPROW row_pointer[1];
    int row_stride;
 
    cinfo.err = jpeg_std_error(&jerr);
    jpeg_create_compress(&cinfo);
 
    if ((outfile = fopen(filename, "wb")) == nullptr)
    {
        yCError(IMAGEFILE, "can't write file: %s\n", filename);
        return false;
    }
    jpeg_stdio_dest(&cinfo, outfile);
 
    cinfo.image_width = w;
    cinfo.image_height = h;
    cinfo.input_components = 3;
    cinfo.in_color_space = JCS_RGB;
    jpeg_set_defaults(&cinfo);
    jpeg_set_quality(&cinfo, quality, TRUE);
 
    jpeg_start_compress(&cinfo, TRUE);
 
    row_stride = w * 3;
 
    while (cinfo.next_scanline < cinfo.image_height)
    {
        row_pointer[0] = (JSAMPROW)&src[cinfo.next_scanline * row_stride];
        (void)jpeg_write_scanlines(&cinfo, row_pointer, 1);
    }
 
    jpeg_finish_compress(&cinfo);
    fclose(outfile);
    jpeg_destroy_compress(&cinfo);
    return true;
#else
    yCError(IMAGEFILE) << "libjpeg not installed";
    return false;
#endif
}
 
bool SavePGM(char *src, const char *filename, size_t h, size_t w, size_t rowSize)
{
    FILE *fp = fopen(filename, "wb");
    if (!fp)
    {
        yCError(IMAGEFILE, "cannot open file %s for writing\n", filename);
        return false;
    }
    else
    {
        const int inc = rowSize; 
 
        fprintf(fp, "P5\n%zu %zu\n%d\n", w, h, 255);
        for (size_t i = 0; i < h; i++)
        {
            fwrite((void *)src, 1, (size_t)w, fp);
            src += inc;
        }
 
        fclose(fp);
    }
 
    return true;
}
 
 
bool SavePPM(char *src, const char *filename, size_t h, size_t w, size_t rowSize)
{
    FILE *fp = fopen(filename, "wb");
    if (!fp)
    {
        yCError(IMAGEFILE, "cannot open file %s for writing\n", filename);
        return false;
    }
    else
    {
        const int inc = rowSize;//YARPSimpleOperation::ComputePadding (w*3, YarpImageAlign) + w * 3;
 
        fprintf(fp, "P6\n%zu %zu\n%d\n", w, h, 255);
        for (size_t i = 0; i < h; i++)
        {
            fwrite((void *)src, 1, (size_t)(w * 3), fp);
            src += inc;
        }
 
        fclose(fp);
    }
 
    return true;
}
 
#if defined (YARP_HAS_ZLIB)
bool SaveFloatCompressed(char* src, const char* filename, size_t h, size_t w, size_t rowSize)
{
    size_t sizeDataOriginal=w*h*sizeof(float);
    size_t sizeDataCompressed = (sizeDataOriginal * 1.1) + 12;
    char* dataCompressed = (char*)malloc(sizeDataCompressed);
 
    int z_result = compress((Bytef*) dataCompressed,(uLongf*) &sizeDataCompressed, (Bytef*)src, sizeDataOriginal);
    switch (z_result)
    {
       case Z_OK:
       break;
 
       case Z_MEM_ERROR:
       yCError(IMAGEFILE, "zlib compression: out of memory");
       return false;
       break;
 
       case Z_BUF_ERROR:
       yCError(IMAGEFILE, "zlib compression: output buffer wasn't large enough");
       return false;
       break;
    }
 
    FILE* fp = fopen(filename, "wb");
    if (fp == nullptr)
    {
        return false;
    }
 
    size_t bw = 0;
    size_t dims[2] = { h,w };
 
    if (fwrite(dims, sizeof(dims), 1, fp) > 0) {
        bw = fwrite((void*)dataCompressed, sizeDataCompressed, 1, fp);
    }
 
    fclose(fp);
    return (bw > 0);
}
#endif
 
bool SaveFloatRaw(char* src, const char* filename, size_t h, size_t w, size_t rowSize)
{
    FILE* fp = fopen(filename, "wb");
    if (fp == nullptr)
    {
        return false;
    }
 
    size_t dims[2] = { h,w };
 
    size_t bw = 0;
    size_t size_ = sizeof(float);
    auto count_ = (size_t)(dims[0] * dims[1]);
 
    if (fwrite(dims, sizeof(dims), 1, fp) > 0) {
        bw = fwrite((void*)src, size_, count_, fp);
    }
 
    fclose(fp);
    return (bw > 0);
}
 
bool ImageWriteJPG(ImageOf<PixelRgb>& img, const char *filename)
{
    return SaveJPG((char*)img.getRawImage(), filename, img.height(), img.width(), img.getRowSize());
}
 
bool ImageWritePNG(ImageOf<PixelRgb>& img, const char *filename)
{
#if defined (YARP_HAS_PNG)
    return SavePNG((char*)img.getRawImage(), filename, img.height(), img.width(), img.getRowSize(), PNG_COLOR_TYPE_RGB, 8);
#else
    yCError(IMAGEFILE) << "YARP was not built with png support";
    return false;
#endif
}
 
bool ImageWritePNG(ImageOf<PixelMono>& img, const char *filename)
{
#if defined (YARP_HAS_PNG)
    return SavePNG((char*)img.getRawImage(), filename, img.height(), img.width(), img.getRowSize(), PNG_COLOR_TYPE_GRAY, 8);
#else
    yCError(IMAGEFILE) << "YARP was not built with png support";
    return false;
#endif
}
 
bool ImageWriteRGB(ImageOf<PixelRgb>& img, const char *filename)
{
    return SavePPM((char*)img.getRawImage(),filename,img.height(),img.width(),img.getRowSize());
}
 
bool ImageWriteMono(ImageOf<PixelMono>& img, const char *filename)
{
    return SavePGM((char*)img.getRawImage(), filename, img.height(), img.width(), img.getRowSize());
}
 
bool ImageWriteFloat_PlainHeaderless(ImageOf<PixelFloat>& img, const char *filename)
{
    return SaveFloatRaw((char*)img.getRawImage(), filename, img.height(), img.width(), img.getRowSize());
}
 
bool ImageWriteFloat_CompressedHeaderless(ImageOf<PixelFloat>& img, const char* filename)
{
#if defined (YARP_HAS_ZLIB)
    return SaveFloatCompressed((char*)img.getRawImage(), filename, img.height(), img.width(), img.getRowSize());
#else
    yCError(IMAGEFILE) << "YARP was not built with zlib support";
    return false;
#endif
}
}
 
// public read methods
 
bool file::read(ImageOf<PixelRgb> & dest, const std::string& src, image_fileformat format)
{
    const char* file_ext = strrchr(src.c_str(), '.');
    if (file_ext==nullptr)
    {
        yCError(IMAGEFILE) << "cannot find file extension in file name";
        return false;
    }
 
    if (strcmp(file_ext, ".pgm")==0 ||
        strcmp(file_ext, ".ppm")==0 ||
        format == FORMAT_PGM ||
        format == FORMAT_PPM)
    {
        return ImageReadRGB_PxM(dest,src.c_str());
    }
    else if(strcmp(file_ext, ".png")==0 ||
            format == FORMAT_PNG)
    {
        return ImageReadRGB_PNG(dest, src.c_str());
    }
    else if(strcmp(file_ext, ".jpg") == 0 ||
            strcmp(file_ext, ".jpeg") == 0 ||
            format == FORMAT_JPG)
    {
        return ImageReadRGB_JPG(dest, src.c_str());
    }
    yCError(IMAGEFILE) << "unsupported file format";
    return false;
}
 
 
bool file::read(ImageOf<PixelBgr> & dest, const std::string& src, image_fileformat format)
{
    const char* file_ext = strrchr(src.c_str(), '.');
    if (file_ext == nullptr)
    {
        yCError(IMAGEFILE) << "cannot find file extension in file name";
        return false;
    }
 
    if (strcmp(file_ext, ".pgm") == 0 ||
        strcmp(file_ext, ".ppm") == 0 ||
        format == FORMAT_PGM ||
        format == FORMAT_PPM)
    {
        return ImageReadBGR_PxM(dest, src.c_str());
    }
    else if (strcmp(file_ext, ".png") == 0 ||
        format == FORMAT_PNG)
    {
        return ImageReadBGR_PNG(dest, src.c_str());
    }
    else if (strcmp(file_ext, ".jpg") == 0 ||
        strcmp(file_ext, ".jpeg") == 0 ||
        format == FORMAT_JPG)
    {
        return ImageReadBGR_JPG(dest, src.c_str());
    }
    yCError(IMAGEFILE) << "unsupported file format";
    return false;
}
 
 
bool file::read(ImageOf<PixelRgba> & dest, const std::string& src, image_fileformat format)
{
    const char* file_ext = strrchr(src.c_str(), '.');
    if (file_ext == nullptr)
    {
        yCError(IMAGEFILE) << "cannot find file extension in file name";
        return false;
    }
 
    if (strcmp(file_ext, ".pgm") == 0 ||
        strcmp(file_ext, ".ppm") == 0 ||
        format == FORMAT_PGM ||
        format == FORMAT_PPM)
    {
        ImageOf<PixelRgb> img2;
        bool ok = ImageReadRGB_PxM(img2, src.c_str());
        if (ok)
        {
            dest.copy(img2);
        }
        return ok;
    }
    else if (strcmp(file_ext, ".png") == 0 ||
             format == FORMAT_PNG)
    {
        ImageOf<PixelRgb> img2;
        bool ok = ImageReadRGB_PNG(img2, src.c_str());
        if (ok)
        {
            dest.copy(img2);
        }
        return ok;
    }
    else if (strcmp(file_ext, ".jpg") == 0 ||
        strcmp(file_ext, ".jpeg") == 0 ||
        format == FORMAT_JPG)
    {
        ImageOf<PixelRgb> img2;
        bool ok = ImageReadRGB_JPG(img2, src.c_str());
        if (ok)
        {
            dest.copy(img2);
        }
        return ok;
    }
    yCError(IMAGEFILE) << "unsupported file format";
    return false;
}
 
bool file::read(ImageOf<PixelMono> & dest, const std::string& src, image_fileformat format)
{
    const char* file_ext = strrchr(src.c_str(), '.');
    if (file_ext == nullptr)
    {
        yCError(IMAGEFILE) << "cannot find file extension in file name";
        return false;
    }
 
    if (strcmp(file_ext, ".pgm") == 0 ||
        strcmp(file_ext, ".ppm") == 0 ||
        format == FORMAT_PGM ||
        format == FORMAT_PPM)
    {
        return ImageReadMono_PxM(dest, src.c_str());
    }
    else if (strcmp(file_ext, ".png") == 0 ||
             format == FORMAT_PNG)
    {
        return ImageReadMono_PNG(dest, src.c_str());
    }
    else if (strcmp(file_ext, ".jpg") == 0 ||
        strcmp(file_ext, ".jpeg") == 0 ||
        format == FORMAT_JPG)
    {
        return ImageReadMono_JPG(dest, src.c_str());
    }
    yCError(IMAGEFILE) << "unsupported file format";
    return false;
}
 
bool file::read(ImageOf<PixelFloat>& dest, const std::string& src, image_fileformat format)
{
    const char* file_ext = strrchr(src.c_str(), '.');
    if (file_ext == nullptr)
    {
        yCError(IMAGEFILE) << "cannot find file extension in file name";
        return false;
    }
 
    if (strcmp(file_ext, ".float") == 0 ||
        format == FORMAT_NUMERIC)
    {
        return ImageReadFloat_PlainHeaderless(dest, src);
    }
    else if (strcmp(file_ext, ".floatzip") == 0 ||
        format == FORMAT_NUMERIC_COMPRESSED)
    {
#if defined (YARP_HAS_ZLIB)
        return ImageReadFloat_CompressedHeaderless(dest, src);
#else
        yCError(IMAGEFILE) << "YARP was not built with zlib support";
        return false;
#endif
    }
    yCError(IMAGEFILE) << "unsupported file format";
    return false;
}
 
 
bool file::write(const ImageOf<PixelRgb> & src, const std::string& dest, image_fileformat format)
{
    if (format == FORMAT_PPM)
    {
        return ImageWriteRGB(const_cast<ImageOf<PixelRgb> &>(src), dest.c_str());
    }
    else  if (format == FORMAT_JPG)
    {
        return ImageWriteJPG(const_cast<ImageOf<PixelRgb> &>(src), dest.c_str());
    }
    else  if (format == FORMAT_PNG)
    {
        return ImageWritePNG(const_cast<ImageOf<PixelRgb> &>(src), dest.c_str());
    }
    else
    {
        yCError(IMAGEFILE) << "Invalid format, operation not supported";
        return false;
    }
}
 
bool file::write(const ImageOf<PixelBgr> & src, const std::string& dest, image_fileformat format)
{
    ImageOf<PixelRgb> imgRGB;
    imgRGB.copy(src);
    if (format == FORMAT_PPM)
    {
        return ImageWriteRGB(const_cast<ImageOf<PixelRgb> &>(imgRGB), dest.c_str());
    }
    else  if (format == FORMAT_JPG)
    {
        return ImageWriteJPG(const_cast<ImageOf<PixelRgb> &>(imgRGB), dest.c_str());
    }
    else  if (format == FORMAT_PNG)
    {
        return ImageWritePNG(const_cast<ImageOf<PixelRgb> &>(imgRGB), dest.c_str());
    }
    else
    {
        yCError(IMAGEFILE) << "Invalid format, operation not supported";
        return false;
    }
}
 
 
bool file::write(const ImageOf<PixelRgba> & src, const std::string& dest, image_fileformat format)
{
    ImageOf<PixelRgb> imgRGB;
    imgRGB.copy(src);
    if (format == FORMAT_PPM)
    {
        return ImageWriteRGB(const_cast<ImageOf<PixelRgb> &>(imgRGB), dest.c_str());
    }
    else  if (format == FORMAT_JPG)
    {
        return ImageWriteJPG(const_cast<ImageOf<PixelRgb> &>(imgRGB), dest.c_str());
    }
    else  if (format == FORMAT_PNG)
    {
        return ImageWritePNG(const_cast<ImageOf<PixelRgb> &>(imgRGB), dest.c_str());
    }
    else
    {
        yCError(IMAGEFILE) << "Invalid format, operation not supported";
        return false;
    }
}
 
 
bool file::write(const ImageOf<PixelMono> & src, const std::string& dest, image_fileformat format)
{
    if (format == FORMAT_PGM)
    {
        return ImageWriteMono(const_cast<ImageOf<PixelMono> &>(src), dest.c_str());
    }
    else  if (format == FORMAT_PNG)
    {
        return ImageWritePNG(const_cast<ImageOf<PixelMono> &>(src), dest.c_str());
    }
    else
    {
        yCError(IMAGEFILE) << "Invalid format, operation not supported";
        return false;
    }
}
 
bool file::write(const ImageOf<PixelFloat>& src, const std::string& dest, image_fileformat format)
{
    if (format == FORMAT_NUMERIC)
    {
        return ImageWriteFloat_PlainHeaderless(const_cast<ImageOf<PixelFloat> &>(src), dest.c_str());
    }
    else if (format == FORMAT_NUMERIC_COMPRESSED)
    {
        return ImageWriteFloat_CompressedHeaderless(const_cast<ImageOf<PixelFloat>&>(src), dest.c_str());
    }
    else
    {
        yCError(IMAGEFILE) << "Invalid format, operation not supported";
        return false;
    }
}
 
bool file::write(const Image& src, const std::string& dest, image_fileformat format)
{
    int code=src.getPixelCode();
    if (code == VOCAB_PIXEL_MONO)
    {
        return write(static_cast<const ImageOf<PixelMono>&>(src), dest, format);
    }
    else if (code == VOCAB_PIXEL_MONO_FLOAT)
    {
        return write(static_cast<const ImageOf<PixelFloat>&>(src), dest, format);
    }
    else if (code == VOCAB_PIXEL_BGR)
    {
        return write(static_cast<const ImageOf<PixelBgr>&>(src), dest, format);
    }
    else if (code == VOCAB_PIXEL_RGB)
    {
        return write(static_cast<const ImageOf<PixelRgb>&>(src), dest, format);
    }
    else if (code == VOCAB_PIXEL_RGBA)
    {
        return write(static_cast<const ImageOf<PixelRgba>&>(src), dest, format);
    }
    else
    {
        ImageOf<PixelRgb> img;
        img.copy(src);
        return write(img,dest);
    }
}