141 lines
4.6 KiB
C++
141 lines
4.6 KiB
C++
/*
|
|
Copyright (c) 2020 CNRS
|
|
All rights reserved.
|
|
|
|
Redistribution and use in source and binary forms, with or without
|
|
modification, are permitted provided that the following conditions are met:
|
|
|
|
1. Redistributions of source code must retain the above copyright notice, this
|
|
list of conditions and the following disclaimer.
|
|
|
|
2. Redistributions 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.
|
|
|
|
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
|
|
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIEDi
|
|
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
|
|
DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER 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.
|
|
*/
|
|
#include <iostream>
|
|
#include <string>
|
|
#include <random>
|
|
#include <vector>
|
|
//Command-line parsing
|
|
#include <CLI11.hpp>
|
|
|
|
//Image filtering and I/O
|
|
#define cimg_display 0
|
|
#include <CImg.h>
|
|
#define STB_IMAGE_IMPLEMENTATION
|
|
#include <stb_image.h>
|
|
#define STB_IMAGE_WRITE_IMPLEMENTATION
|
|
#include <stb_image_write.h>
|
|
|
|
unsigned char min(unsigned char a, unsigned char b) {
|
|
return a < b ? a : b;
|
|
}
|
|
unsigned char max(unsigned char a, unsigned char b) {
|
|
return a > b ? a : b;
|
|
}
|
|
|
|
//Global flag to silent verbose messages
|
|
bool silent;
|
|
|
|
|
|
int main(int argc, char **argv)
|
|
{
|
|
CLI::App app{"equalization"};
|
|
std::string sourceImage;
|
|
app.add_option("-s,--source", sourceImage, "Source image")->required()->check(CLI::ExistingFile);
|
|
std::string outputImage= "output.png";
|
|
app.add_option("-o,--output", outputImage, "Output image")->required();
|
|
unsigned int nbSteps = 3;
|
|
app.add_option("-n,--nbsteps", nbSteps, "Number of sliced steps (3)");
|
|
silent = false;
|
|
app.add_flag("--silent", silent, "No verbose messages");
|
|
CLI11_PARSE(app, argc, argv);
|
|
|
|
//Image loading
|
|
int width,height, nbChannels;
|
|
unsigned char *source = stbi_load(sourceImage.c_str(), &width, &height, &nbChannels, 0);
|
|
if (!silent) std::cout<< "Source image: "<<width<<"x"<<height<<" ("<<nbChannels<<")"<< std::endl;
|
|
if (nbChannels < 3)
|
|
{
|
|
std::cout<< "Input images must be RGB images."<<std::endl;
|
|
exit(1);
|
|
}
|
|
|
|
//Main computation
|
|
std::vector<unsigned char> output(width*height*nbChannels);
|
|
|
|
//As an example, we just scan the pixels of the source image
|
|
//and swap the color channels.
|
|
unsigned int cum_r[255];
|
|
unsigned int cum_g[255];
|
|
unsigned int cum_b[255];
|
|
for (auto i=0; i < 255; i++) {
|
|
cum_r[i] = cum_g[i] = cum_b[i] = 0;
|
|
}
|
|
|
|
for(auto i = 0 ; i < width ; ++i) {
|
|
for(auto j = 0; j < height; ++j) {
|
|
auto indexPixel = nbChannels*(width*j+i);
|
|
cum_r[source[ indexPixel ]]++;
|
|
cum_g[source[indexPixel+1]]++;
|
|
cum_b[source[indexPixel+2]]++;
|
|
}
|
|
}
|
|
|
|
unsigned int distrib_r[255];
|
|
unsigned int distrib_g[255];
|
|
unsigned int distrib_b[255];
|
|
|
|
int total_px = width*height;
|
|
int cur_cum_r, cur_cum_g, cur_cum_b;
|
|
cur_cum_r, cur_cum_g, cur_cum_b = 0;
|
|
for (auto i=0; i < 255; i++) {
|
|
cur_cum_r += cum_r[i];
|
|
cur_cum_g += cum_g[i];
|
|
cur_cum_b += cum_b[i];
|
|
distrib_r[i] = 255*cur_cum_r/total_px;
|
|
distrib_g[i] = 255*cur_cum_g/total_px;
|
|
distrib_b[i] = 255*cur_cum_b/total_px;
|
|
}
|
|
|
|
for(auto i = 0 ; i < width ; ++i)
|
|
{
|
|
for(auto j = 0; j < height; ++j)
|
|
{
|
|
auto indexPixel = nbChannels*(width*j+i);
|
|
unsigned char r = source[ indexPixel ];
|
|
unsigned char g = source[ indexPixel + 1];
|
|
unsigned char b = source[ indexPixel + 2];
|
|
//Swapping the channels
|
|
output[ indexPixel ] = distrib_r[r];
|
|
output[ indexPixel + 1 ] = distrib_g[g];
|
|
output[ indexPixel + 2 ] = distrib_b[b];
|
|
if (nbChannels == 4) //just copying the alpha value if any
|
|
output[ indexPixel + 3] = source[ indexPixel + 3];
|
|
}
|
|
}
|
|
|
|
//Final export
|
|
if (!silent) std::cout<<"Exporting.."<<std::endl;
|
|
int errcode = stbi_write_png(outputImage.c_str(), width, height, nbChannels, output.data(), nbChannels*width);
|
|
if (!errcode)
|
|
{
|
|
std::cout<<"Error while exporting the resulting image."<<std::endl;
|
|
exit(errcode);
|
|
}
|
|
|
|
stbi_image_free(source);
|
|
exit(0);
|
|
}
|