void Compute(const ImageRGB<byte>& image, const ImageHSV<byte>& imagehsv) {
const int& w = image.GetWidth();
const int& h = image.GetHeight();
label_map.Resize(h, w);
// Compute pixel-wise features
pixel_ftrs.Compute(image, imagehsv);
// Run K-means to generate textons
vector<VecD> points;
const vector<VecD>& ftrs = pixel_ftrs.features;
random_sample_n(ftrs.begin(), ftrs.end(), back_inserter(points), 5000);
VecI labels(points.size());
KMeans::Estimate(points, 20, textons, labels);
// Label the pixels
for (int r = 0; r < h; r++) {
for (int c = 0; c < w; c++) {
const VecD& ftr = (*pixel_ftrs.feature_map)(r, c);
double mindist = INFINITY;
for (int i = 0; i < textons.size(); i++) {
const double dist = VectorSSD(textons[i], ftr);
if (dist < mindist) {
mindist = dist;
label_map[r][c] = i;
}
}
}
}
}
void Pointcloud::subSampleRandom(unsigned int num_samples, Pointcloud& sample_cloud) {
point3d_collection samples;
// visual studio does not support random_sample_n
#ifdef _MSC_VER
samples.reserve(this->size());
samples.insert(samples.end(), this->begin(), this->end());
std::random_shuffle(samples.begin(), samples.end());
samples.resize(num_samples);
#else
random_sample_n(begin(), end(), std::back_insert_iterator<point3d_collection>(samples), num_samples);
for (unsigned int i=0; i<samples.size(); i++) {
sample_cloud.push_back(samples[i]);
}
#endif
}
void random_samples(list<string> g,int K, list<string> &sol)
{
//vector<string> gg(all(g));
vector<string> gg(all(g));
random_shuffle(all(gg));
vector<string> s(K);
srand((unsigned)time(0));
random_sample_n(all(gg),s.begin(),K);
//random_shuffle(all(s));
for(int i = 0; i < K; i++)
{
sol.push_back(s[i]);
}
}
inline OutputIter random_sample_n(InputIter first, InputIter last, OutputIter out, Size n) {
std::random_device rd;
std::mt19937 rand{rd()};
return random_sample_n(first, last, out, n, rand);
} // random_sample_n
inline OutputIter random_sample_n(InputIter first, InputIter last, OutputIter out, Size n) {
std::mt19937 rand;
rand.seed(std::time(0));
return random_sample_n(first, last, out, n, rand);
} // random_sample_n
