miniprojet/tests/src/math.hpp

349 lines
8.5 KiB
C++

#pragma once
#include <vector>
#include <complex>
#include <opencv2/opencv.hpp>
#include <iterator>
#include <cmath>
namespace math {
using complex = std::complex<double>;
using signal = std::vector<double>;
using csignal = std::vector<complex>;
using contour = std::vector<cv::Point>;
constexpr double pi() {return std::atan(1)*4;}
void display_abs(const csignal& s) {
int count=0;
for (auto d: s) {
std::cout << count++ << ' ' << std::abs(d) << std::endl;
}
}
void display(const contour& s) {
int count=0;
for (auto d: s) {
std::cout << count++ << ' ' << d.x << ' ' << d.y << std::endl;
}
}
void display(const csignal& s) {
int count=0;
for (auto d: s) {
std::cout << count++ << ' ' << d.real() << ' ' << d.imag() << std::endl;
}
}
void to_binary(const cv::Mat& img, cv::Mat& output) {
for (int index=0,indexNB=0;index<3*img.rows*img.cols;index+=3,indexNB++) {
unsigned char B = img.data[index ];
unsigned char G = img.data[index+1];
unsigned char R = img.data[index+2];
if (float(R + B + G)/3 > 127) {
output.data[indexNB]=0;
} else {
output.data[indexNB]=255;
}
}
}
void filter(const cv::Mat& img, cv::Mat& output, int seuil) {
bool detect = false;
uchar R, G, B;
int rows = img.rows;
int cols = img.cols;
int dim = img.channels();
int indexNB;
for (int index=0,indexNB=0;index<dim*rows*cols;index+=dim,indexNB++) {
detect = false;
B = img.data[index ];
G = img.data[index+1];
R = img.data[index+2];
if ((R>G) && (R>B)) {
if (((R-B)>=seuil) || ((R-G)>=seuil)) {
output.data[indexNB]=255;
} else {
output.data[indexNB]=0;
}
}
}
}
csignal cont2sig(const contour& cont) {
csignal sig;
for (auto p: cont) {
sig.push_back(complex(p.x, p.y));
}
return sig;
};
complex mean(const csignal& sig) {
complex res = 0;
for (auto x: sig) {
res += x;
}
return complex(res.real()/sig.size(), res.imag()/sig.size());
};
csignal diff(const csignal& input, complex mean) {
csignal res;
for (auto x: input) {
res.push_back(x-mean);
}
return res;
}
csignal& dft(const csignal& input) {
csignal* res = new csignal();
int size = input.size();
for (int k=0; k<size; ++k) {
complex t=0;
for (int n=0; n<size; ++n) {
t += (input[n] * std::exp(complex(0, -2*pi()*n*k/size)));
}
res->push_back(t);
}
return *res;
}
csignal fft_rec(const csignal& input) { //TODO: implémenter la fft !!!
int size = input.size();
if (size <= 1) {
return input;
} else if (size == 2) {
csignal res;
res.push_back(input[0]+input[1]);
res.push_back(input[0]-input[1]);
return res;
} else if (size == 3) {
csignal res;
complex e2 = std::exp(complex(0, -2*pi()/3));
complex e4 = std::exp(complex(0, -4*pi()/3));
complex e8 = std::exp(complex(0, -8*pi()/3));
res.push_back(input[0]+input[1]+input[2]);
res.push_back(input[0]+input[1]*e2+input[2]*e4);
res.push_back(input[0]+input[1]*e4+input[2]*e8);
return res;
} else {
csignal odd;
csignal even;
auto odd_back_it = std::back_inserter(odd);
auto even_back_it = std::back_inserter(even);
bool insert_in_even = true;
for (auto it = input.begin(); it != input.end(); ++it) {
if (insert_in_even) {
*(even_back_it++) = *it;
insert_in_even = false;
} else {
*(odd_back_it++) = *it;
insert_in_even = true;
}
}
csignal res(size, complex());
csignal odd_fft = fft_rec(odd);
csignal even_fft = fft_rec(even);
for (int k=0; k<size/2; ++k) {
complex t = std::exp(complex(0, -2*pi()*k/size)) * odd_fft[k];
res[k] = even_fft[k] + t;
res[size/2+k] = even_fft[k] - t;
}
return res;
}
}
csignal fft(const csignal& input, int N=0) {
int opt_size;
if (N < input.size()) {
opt_size = 1 << (int)std::ceil(std::log(input.size())/std::log(2));
} else if (N==0){
opt_size = input.size();
} else {
opt_size = 1 << (int)std::ceil(std::log(N)/std::log(2));
}
opt_size = input.size();
csignal sig(input);
for (int i=0; i<opt_size-input.size(); ++i) {
sig.push_back(complex(0, 0));
}
return fft_rec(sig);
};
void operator*=(csignal& sig, complex& m) {
for(auto x: sig) {
x *= m;
}
}
void operator*=(csignal& sig, complex&& m) {
for(auto x: sig) {
x *= m;
}
}
void operator/=(csignal& sig, complex& m) {
for(auto x: sig) {
x /= m;
}
}
void operator/=(csignal& sig, complex&& m) {
for(auto x: sig) {
x /= m;
}
}
csignal extract(const csignal& tfd, int cmin, int cmax) {
csignal res;
int kmin = tfd.size()/2 + cmin;
int kmax = tfd.size()/2 + cmax;
auto tfd_it = tfd.end() + cmin;
for (int k=0; k<-cmin; ++k) {
res.push_back(*(tfd_it++));
}
tfd_it = tfd.begin();
for (int k=0; k<cmax+1; ++k) {
res.push_back(*(tfd_it++));
}
return res;
}
contour sig2cont(const csignal& sig) {
contour res;
for (auto x: sig) {
res.push_back(cv::Point(x.real(), x.imag()));
}
res.push_back(res[0]);
return res;
}
csignal desc2sig(const csignal& desc, complex mean, int N, int cmin, int cmax) { //TODO: retirer cmax des arguments
csignal cont;
auto desc_it = desc.begin();
for (int m=0; m<N; ++m) {
complex sum = 0;
auto d_it = desc.begin();
for (int k=0; k<desc.size(); ++k) {
sum += *(d_it++)*std::exp(complex(0, 2*pi()*(k+cmin)*m/N));
}
cont.push_back(mean + sum);
}
return cont;
};
std::array<int, 4> bounds(const contour& cont) {
std::array<int, 4> res = {cont[0].x, cont[0].y, cont[0].x, cont[0].y};
for (auto p: cont) {
if (res[0] > p.x) {
res[0] = p.x;
}
if (res[1] > p.y) {
res[1] = p.y;
}
if (res[2] < p.x) {
res[2] = p.x;
}
if (res[3] < p.y) {
res[3] = p.y;
}
}
return res;
}
int x_to_cv(double x, int xmin, int xmax, int width) {
double a = 0.8 * float(width) / (xmax - xmin);
double b = 0.1 * float(width) - a * xmin;
return (a * x + b);
}
int y_to_cv(double x, int ymin, int ymax, int width) {
double a = 0.8 * float(width) / (ymin - ymax);
double b = 0.1 * float(width) - a * ymax;
return (a * x + b);
}
contour transform(contour& cont, std::array<int, 4>& bounds, int size) {
contour res;
for (auto p: cont) {
int px = x_to_cv(p.x, bounds[0], bounds[2], size);
int py = x_to_cv(p.y, bounds[1], bounds[3], size);
res.push_back(cv::Point(px, py));
}
return res;
}
csignal descriptors(const contour& cont, int cmax) {
csignal z = cont2sig(cont);
complex zm = mean(z);
csignal tfd = dft(diff(z, zm));
tfd /= z.size();
int cmin = -cmax;
csignal desc = extract(tfd, cmin, cmax);
if (std::abs(desc[desc.size()/2-1]) > std::abs(desc[desc.size()/2+1])) {
std::reverse(desc.begin(), desc.end());
}
double phy = std::arg(desc[desc.size()/2-1]*desc[desc.size()/2+1])/2;
desc *= std::exp(complex(0, -phy));
double theta = std::arg(desc[desc.size()/2+1]);
for (int k=0; k<desc.size(); ++k) {
desc[k] *= std::exp(complex(0, -theta*(k-cmin)));
}
desc /= std::abs(desc[desc.size()/2+1]);
return desc;
}
contour simplify_contour(const contour& cont, int cmax) {
csignal z = cont2sig(cont);
complex zm = mean(z);
csignal tfd = dft(diff(z, zm));
tfd /= z.size();
int cmin = -cmax;
csignal desc = extract(tfd, cmin, cmax);
if (std::abs(desc[desc.size()/2-1]) > std::abs(desc[desc.size()/2+1])) {
std::reverse(desc.begin(), desc.end());
}
double phy = std::arg(desc[desc.size()/2-1]*desc[desc.size()/2+1])/2;
desc *= std::exp(complex(0, -phy));
double theta = std::arg(desc[desc.size()/2+1]);
for (int k=0; k<desc.size(); ++k) {
desc[k] *= std::exp(complex(0, -theta*(k-cmin)));
}
desc /= std::abs(desc[desc.size()/2+1]);
/*
*/
csignal sig = desc2sig(desc, zm, z.size(), cmin, cmax);
return sig2cont(sig);
};
int max_cont(const std::vector<contour>& contours) {
int max = 0;
int id = 0;
for (int i=0; i<contours.size(); ++i) {
if (contours[i].size() > max) {
max = contours[i].size();
id = i;
}
}
return id;
};
}