FilePng.h

/*
 
MIT License
 
Copyright (c) 2017 FMI Open Development / Markus Peura, first.last@fmi.fi
 
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.
 
*/
/*
Part of Rack development has been done in the BALTRAD projects part-financed
by the European Union (European Regional Development Fund and European
Neighbourhood Partnership Instrument, Baltic Sea Region Programme 2007-2013)
*/
#ifndef FILEPNG_H_
#define FILEPNG_H_
 
 
#include <string>
#include <iostream>
#include <fstream>
#include <exception>
 
#include <png.h>
 
#include "drain/util/FileInfo.h"
// #include "drain/util/RegExp.h"
#include "drain/util/JSON.h" // for reading attribute value
 
#include "Image.h"
//
 
 
namespace drain
{
namespace image
{
 
// using namespace std;
 
 
class FilePng
{
public:
 
    //static
    //const drain::RegExp fileNameRegExp;
 
 
 
    template <class T>
    static
    void readOld(T & image, const std::string &path, int png_transforms = 0);  //(PNG_TRANSFORM_PACKING || PNG_TRANSFORM_EXPAND));  16 >> 8?
 
    static
    void read(ImageFrame & image, const std::string &path, int png_transforms = 0);  //(PNG_TRANSFORM_PACKING || PNG_TRANSFORM_EXPAND));  16 >> 8?
 
    // consider readFrame() like with PNM
 
 
    static void write(const ImageFrame &image, const std::string &path);
 
    static FileInfo fileInfo;
 
    static
    short int compressionLevel;
 
protected:
    static FileInfo & initFileInfo;  //???
 
};
 
 
template <class T> // , const CommentReader & commentReader = CommentReader()
void FilePng::readOld(T & image, const std::string & path, int png_transforms ) {
 
    drain::Logger mout(getImgLog(), __FILE__, __FUNCTION__);
 
    mout.debug("path='" , path , "'" );
 
 
    // Try to open the file
    FILE *fp = fopen(path.c_str(), "rb");
    if (fp == NULL){
        throw std::runtime_error(std::string("FilePng: could not open file: ") + path);
    }
 
    // For checking magic code (signature)
    //const unsigned int PNG_BYTES_TO_CHECK=4;
    const size_t PNG_BYTES_TO_CHECK=4;
    png_byte buf[PNG_BYTES_TO_CHECK];
 
    /* Read in some of the signature bytes */
    if (fread((void *)buf, size_t(1), PNG_BYTES_TO_CHECK, fp) != PNG_BYTES_TO_CHECK){
        fclose(fp);
        throw std::runtime_error(std::string("FilePng: suspicious size of file: ") + path);
    }
 
    /* Compare the first PNG_BYTES_TO_CHECK bytes of the signature.
       Return nonzero (true) if they match */
    if (png_sig_cmp(buf, (png_size_t)0, PNG_BYTES_TO_CHECK) != 0){
        fclose(fp);
        throw std::runtime_error(std::string("FilePng: not a png file: ") + path);
    }
 
 
    png_structp  png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
    if (!png_ptr){
        fclose(fp);
        throw std::runtime_error(std::string("FilePng: problem in allocating image memory for: ")+path);
    }
 
    png_infop info_ptr = png_create_info_struct(png_ptr);
    if (!info_ptr){
        fclose(fp);
        png_destroy_read_struct(&png_ptr,(png_infopp)NULL, (png_infopp)NULL);
        throw std::runtime_error(std::string("FilePng: problem in allocating info memory for: ")+path);
    }
 
    /*
    png_infop end_info = png_create_info_struct(png_ptr);
    if (!end_info){
        png_destroy_read_struct(&png_ptr, &info_ptr,(png_infopp)NULL);
        throw std::runtime_error(std::string("FilePng: problem in allocating end_info memory for: ")+path);
    }
    */
 
    // This may be unstable. According to the documentation, if one uses the high-level interface png_read_png()
    // one can only configure it with png_transforms flags (PNG_TRANSFORM_*)
    png_set_palette_to_rgb(png_ptr);
 
    png_init_io(png_ptr, fp);
    png_set_sig_bytes(png_ptr, PNG_BYTES_TO_CHECK);
 
    //if (drain::Debug > 2)
    mout.debug3("reading data" );
 
    png_read_png(png_ptr, info_ptr, png_transforms, NULL);
 
 
 
 
 
    mout.debug3("reading image comments" );
    int num_text = 0;
    png_textp text_ptr = NULL;
    png_get_text(png_ptr, info_ptr,&text_ptr, &num_text);
    //mout.debug3() << '\n';
    for (int i = 0; i < num_text; ++i) {
        mout << text_ptr[i].key << '=' << text_ptr[i].text << '\n';
        // ValueReader::scanValue(text_ptr[i].text, image.properties[text_ptr[i].key]);
        JSON::readValue(text_ptr[i].text, image.properties[text_ptr[i].key]);
    }
    mout << mout.endl;
 
 
    const unsigned int inputBitDepth = png_get_bit_depth(png_ptr, info_ptr);
    drain::Type t;
    switch (inputBitDepth) {
    case 16:
        //image.initialize<unsigned short>();
        t.setType<unsigned short>();
        break;
    case 8:
        t.setType<unsigned char>();
        break;
    default:
        fclose(fp);
        png_destroy_read_struct(&png_ptr,&info_ptr, (png_infopp)NULL);
        //png_free_data(png_ptr,info_ptr,PNG_FREE_ALL,-1);  // ???
        throw std::runtime_error(std::string("FilePng: unsupported bit depth in : ")+path);
        return;
    }
 
    //image.setType(t);
    mout.debug("initialize, type " , image.getType().name() );
 
    const unsigned int width  = png_get_image_width(png_ptr, info_ptr);
    const unsigned int height = png_get_image_height(png_ptr, info_ptr);
    const unsigned int channels = png_get_channels(png_ptr, info_ptr);
 
 
    Geometry g(image.getGeometry());
 
    // This test enables read into an alpha channel.
    if  ((channels!=g.channels.getChannelCount()) || (width!=g.area.getWidth()) || (height!=g.area.getHeight())){
        switch (channels) {
        case 4:
            g.set(width,height,3,1);
            break;
        case 3:
            g.setGeometry(width,height,3); // check alpha=0!
            break;
        case 2:
            g.set(width,height,1,1);
            break;
        case 1:
            g.setGeometry(width,height,1); // check alpha=0!
            break;
        default:
            throw std::runtime_error(std::string("FilePng: invalid channel count in : ")+path);
        }
    }
 
    // Form Image, set target type and geometry. For ImageFrame, compare target type and geometry. If differences, throw exception.
    image.initialize(t, g);
 
    mout.debug3() << "png geometry ok, ";
    mout << "png channels =" << channels << "\n";
    mout << "png bit_depth=" << inputBitDepth << "\n";
    mout << mout.endl;
 
    // TODO: use png_get_pCal(.........)
#ifdef PNG_pCAL_SUPPORTED___DEFUNCT
    if (info_ptr->pcal_X0 == info_ptr->pcal_X1){
        mout.toOStr() << "physical scale supported, but no intensity range, pcalX0=" <<  info_ptr->pcal_X0 << ", pcalX1=" <<  info_ptr->pcal_X1  << mout.endl;
        image.setDefaultLimits();
    }
    else {
        image.setLimits(info_ptr->pcal_X0, info_ptr->pcal_X1);
        mout.note("setting physical scale: " , image );
    }
 
#endif
 
    /*
     if ((bit_depth!=8) && (bit_depth != 16)){
        fclose(fp);
        png_destroy_read_struct(&png_ptr,&info_ptr, (png_infopp)NULL);
        //png_free_data(png_ptr,info_ptr,PNG_FREE_ALL,-1);  // ???
        throw std::runtime_error(std::string("FilePng: unsupported bit depth in : ")+path);
    }
    */
    const unsigned int targetBitDepth = 8*image.getConf().getElementSize();
 
    const bool from8to8  = (inputBitDepth == 8) && (targetBitDepth ==  8);
    const bool from8to16 = (inputBitDepth == 8) && (targetBitDepth == 16);
 
    if (from8to8) {
        mout.debug("8-bit input, 8-bit target, easy..." );
    }
    else if (from8to16) {
        mout.note("-bit input, 16-bit target, rescaling..." );
    }
    else {
        if ((inputBitDepth == 16) && (targetBitDepth == 16)){
            mout.debug("16-bit input, 16-bit target, ok..." );
        }
        else {
            mout.warn(inputBitDepth , "-bit input, ", targetBitDepth , "-bit target, problems ahead?" );
        }
    }
 
    png_bytep *row_pointers = png_get_rows(png_ptr, info_ptr);
    png_bytep p;
    int i0;
    for (unsigned int j = 0; j < height; ++j) {
        p = row_pointers[j];
        for (unsigned int i = 0; i < width; ++i) {
            for (unsigned int k = 0; k < channels; ++k) {
                i0 = channels*i + k;
                if (from8to8) {
                    image.put(i,j,k, p[i0]);
                }
                else if (from8to16) {
                    image.put(i,j,k, p[i0]<<8);
                }
                else {
                    image.put(i,j,k, (p[i0*2]<<8) + (p[i0*2+1]<<0));
                }
            }
        }
    }
 
    fclose(fp);
    png_destroy_read_struct(&png_ptr,&info_ptr, (png_infopp)NULL);
    //png_free_data(png_ptr,info_ptr,PNG_FREE_ALL,-1);  // ???
 
    //png_destroy_read_struct(&png_ptr,(png_infopp)NULL, (png_infopp)NULL);
    //png_destroy_info_struct(png_ptr,&info_ptr);
 
 
}
 
 
 
}
 
}
 
#endif /*FILEPng_H_*/
 
// Drain