int xlocal = i%ditherSize;
int ylocal = j%ditherSize;
double dither = ditherLookup[xlocal + ylocal * 4];#include "stdafx.h"
#include <iostream>
#include<algorithm>
#include<iterator>
#include<fstream>
#include<vector>
#include<cassert>
#include <ctime>
#include <sstream>
using namespace std;
vector<vector<int>> make_gradient(int height, int width)
{
assert(height > 0 && width > 0);
int cf = height / 255;
int color = 0;
vector<vector<int>> result(height, vector<int>(width));
for (int i = 0; i < height; i += cf)
{
for (int j = 0; j < cf; ++j)
{
fill(result[i + j].begin(), result[i + j].end(), color % 255);
}
color++;
}
stable_sort(result.begin(), result.end());
return result;
}
vector<vector<int>> ordered_dither(int height, int width)
{
int ditherSize = 4;
int ditherLookup[] = { 0, 8, 2, 10, 12, 4, 14, 6, 3, 11, 1, 9, 15, 7, 13, 5 };
vector<vector<int>> result(height, vector<int>(width));
for (int i = 0; i < height; i++)
{
double target = ((double)i + 0.5)*255.0 / height;
for (int j = 0; j < width; j++)
{
int xlocal = i%ditherSize;
int ylocal = j%ditherSize;
double dither = ditherLookup[xlocal + ylocal * 4];
int val = (int)round(target + dither);
if (val < 0)
val = 0;
if (val > 255)
val = 255;
result[i][j] = val;
}
}
return result;
}
vector<vector<int>> random_dither(int height, int width)
{
assert(height > 0 && width > 0);
vector<vector<int>> result(height, vector<int>(width));
for (int i = 0; i < height; ++i)
{
double target = ((double)i + 0.5)*255.0 / height;
for (int j = 0; j < width; ++j)
{
double dither = ((double)rand() - (double)rand()) / RAND_MAX;
int val = (int)round(target + dither);
if (val < 0)
val = 0;
if (val > 255)
val = 255;
result[i][j] = val;
}
}
return result;
}
vector<vector<int>> fs_dither(int height, int width)
{
vector<vector<int>> result(height, vector<int>(width));
for (int i = 0; i < height; i++)
{
for (int j = 0; j < width; j++)
{
result[i][j] = ((double)i + 0.5)*255.0 / width;
}
}
for (int i = 0; i < height - 1; i++)
{
for (int j = 0; j < width - 1; j++)
{
int oldpixel = result[i][j];
int newpixel = round(oldpixel);
result[i][j] = newpixel;
int quanterror = oldpixel - newpixel;
if (j < width - 1) {
result[i][j + 1] += quanterror * 7 / 16;
}
if (i < height - 1) {
if (j > 0) {
result[i + 1][j - 1] += quanterror * 3 / 16;
}
result[i + 1][j] += quanterror * 5 / 16;
if (j < width - 1) {
result[i + 1][j + 1] += quanterror * 1 / 16;
}
}
}
}
return result;
}
vector<vector<int>> jjn_dither(int height, int width)
{
vector<vector<int>> result(height, vector<int>(width));
for (int i = 0; i < height; i++)
{
for (int j = 0; j < width; j++)
{
result[i][j] = ((double)i + 0.5)*255.0 / width;
}
}
for (int i = 0; i < height; i++)
{
for (int j = 0; j < width; j++)
{
int oldpixel = result[i][j];
int newpixel = round(result[i][j]);;
result[i][j] = newpixel;
int quanterror = oldpixel - newpixel;
if (j < width - 1) {
result[i][j + 1] += quanterror * 7 / 48;
if (j<width - 2)
result[i][j + 2] += quanterror * 5 / 48;
}
if (i < height - 1) {
if (j > 0) {
if (j > 1)
result[i + 1][j - 2] += quanterror * 3 / 48;
result[i + 1][j - 1] += quanterror * 5 / 48;
}
result[i + 1][j] += quanterror * 7 / 48;
if (j < width - 1) {
result[i + 1][j + 1] += quanterror * 5 / 48;
if (j < width - 2)
result[i + 1][j + 2] += quanterror * 3 / 48;
}
}
if (i < height - 2) {
if (j > 0) {
if (j>1)
result[i + 2][j - 2] += quanterror * 1 / 48;
result[i + 2][j - 1] += quanterror * 3 / 48;
}
result[i + 2][j] += quanterror * 5 / 48;
if (j < width - 1) {
result[i + 2][j + 1] += quanterror * 3 / 48;
if (j < width - 2)
result[i + 2][j + 2] += quanterror * 1 / 48;
}
}
}
}
return result;
}
int main(int argc, char *argv[])
{
if (argc < 5) {
cout << "usage:" << endl << "prog.exe <filename> <width> <height> <dithering>" << endl;
return 0;
}
stringstream w(argv[2]);
stringstream h(argv[3]);
stringstream d(argv[4]);
int numcols, numrows, dithering;
if (!(w >> numcols)) {
cout << "width is not a number" << endl;
return 0;
}
if (numcols < 1) {
cout << "width must be more than zero" << endl;
return 0;
}
if (!(h >> numrows)) {
cout << "height is not a number" << endl;
return 0;
}
if (numrows < 1) {
cout << "height must be more than zero" << endl;
return 0;
}
if (!(d >> dithering)) {
cout << "dithering is not a number" << endl;
return 0;
}
if (dithering < 0 || dithering>4) {
cout << "dithering must be [0-4]" << endl;
return 0;
}
srand(time(0));
ofstream file;
file.open(argv[1]);
if (!file)
{
cout << "can't open file" << endl;
return 0;
}
file << "P5" << "\n";
file << numrows << " " << numcols << "\n";
file << 255 << "\n";
vector<vector<int>> pixmap;
switch (dithering) {
case 0:
pixmap = make_gradient(numrows, numcols);
break;
case 1:
pixmap = ordered_dither2(numrows, numcols);
break;
case 2:
pixmap = random_dither(numrows, numcols);
break;
case 3:
pixmap = fs_dither(numrows, numcols);
break;
case 4:
pixmap = jjn_dither(numrows, numcols);
break;
default:
break;
}
for_each(pixmap.begin(), pixmap.end(), [&](const auto& v) {
copy(v.begin(), v.end(), ostream_iterator<char>{file, ""});
});
file.close();
}
И это не помогло