std::vector<Index> partition(Count k, Count n, Rng& rng) {
struct P {
Index idx;
Count sz;
bool operator<(const P& p) const {
return sz < p.sz;
}
};
std::vector<P> ps(n, {0, 0});
auto i = 0;
for (auto& p : ps) p.idx = i++;
auto cs = GenerateClusters(n, rng);
for (auto c : cs) {
++ps[c].sz;
}
std::partial_sort(ps.begin(), ps.end()-k, ps.end());
std::vector<bool> res(ps.size(), true);
for (auto i = 0; i < n-k; ++i) {
res[ps[i].idx] = false;
}
DecreaseClustering(cs, res);
auto it = std::remove_if(centers_.begin(), centers_.end(), [&](Index c){ return cs[c] == -1; });
centers_.erase(it, centers_.end());
auto redoCount = std::count(cs.begin(), cs.end(), -1);
std::vector<Index> origs;
origs.reserve(redoCount);
for (int i = 0; i < cs.size(); ++i) {
if (cs[i] != -1) origs.push_back(i);
}
return GenerateClusters(origs);
}
std::vector<Index> GenerateClusters(Count k, Rng& rng) {
std::vector<Index> clusters(g.nodeCount());
std::uniform_int_distribution<> distr_v(0, g.nodeCount()-1);
auto& origs = centers_;
origs.clear();
for (auto i = 0; i < k;) {
auto n = distr_v(rng);
auto it = lower_bound(origs.begin(), origs.end(), n);
if (*it == n) {
continue;
}
// vector...
origs.insert(it, n);
++i;
}
return GenerateClusters(origs);
}
// bool TePDIIsosegClas::Implementation(const TePDIParameters& params)
bool TePDIIsosegClas::RunImplementation()
{
// Setting the parameters
TePDITypes::TePDIRasterVectorType input_rasters;
params_.GetParameter("input_rasters", input_rasters);
vector<int> bands;
params_.GetParameter("bands", bands);
W = input_rasters[0]->params().ncols_;
H = input_rasters[0]->params().nlines_;
TePDITypes::TePDIPolygonSetPtrType input_polygonset;
params_.GetParameter("input_polygonset", input_polygonset);
TePDITypes::TePDIRasterPtrType output_raster;
params_.GetParameter("output_raster", output_raster);
double acceptance_limiar;
params_.GetParameter("acceptance_limiar", acceptance_limiar);
/* Setting the output raster */
TeRasterParams output_raster_params = output_raster->params();
output_raster_params.setDataType( TeDOUBLE, -1 );
output_raster_params.nBands( 1 );
if( input_rasters[0]->projection() != 0 ) {
TeSharedPtr< TeProjection > proj( TeProjectionFactory::make(
input_rasters[0]->projection()->params() ) );
output_raster_params.projection( proj.nakedPointer() );
}
output_raster_params.boxResolution( input_rasters[0]->params().box().x1(),
input_rasters[0]->params().box().y1(), input_rasters[0]->params().box().x2(),
input_rasters[0]->params().box().y2(), input_rasters[0]->params().resx_,
input_rasters[0]->params().resy_ );
// output_raster_params.setPhotometric( TeRasterParams::TeRGB, -1 );
TEAGN_TRUE_OR_RETURN( output_raster->init( output_raster_params ),
"Output raster reset error" );
for (unsigned pols = 0; pols < input_polygonset->size(); pols++)
{
TePolygon polygon(input_polygonset->operator[](pols));
// this iterator "walks" in the image, on the region defined by a specific polygon
TeRaster::iteratorPoly it = input_rasters[0]->begin(polygon, TeBoxPixelIn, 0);
TeRaster::iteratorPoly it_end = input_rasters[0]->end(polygon, TeBoxPixelIn, 0);
long area = (long)TeGeometryArea(polygon);
// pixel vector for each band
vector<vector<double> > pixels_per_band(bands.size());
vector<double> sums(bands.size());
vector<double> tmp(1);
for (unsigned band = 0; band < bands.size(); band++)
pixels_per_band.push_back(tmp);
long npix = 0;
double tmp_pixel;
while(it != it_end)
{
int col = it.currentColumn(),
lin = it.currentLine();
if ((col >= 0 && col < W) && (lin >=0 && lin < H))
{
for (unsigned band = 0; band < bands.size(); band++)
{
input_rasters[band]->getElement(col, lin, tmp_pixel, band);
pixels_per_band[band].push_back(tmp_pixel);
sums[band] += tmp_pixel;
}
npix++;
}
++it;
}
vector<double> tmp_mean;
tmp_mean.reserve(bands.size());
for (unsigned band = 0; band < bands.size(); band++)
{
tmp_mean.push_back(sums[band]/npix);
}
// sets the covarariance matrix
TeMatrix tmp_covar;
int nbands = bands.size();
TEAGN_TRUE_OR_RETURN(tmp_covar.Init(nbands, nbands, 0.0), "Unable to Init tmp_covar");
double sum;
for(int i = 0; i < nbands; i++)
for(int j = 0; j < nbands; j++)
{
sum = 0.0;
for (int p = 0; p < npix; p++)
sum += (pixels_per_band[i][p] - tmp_mean[i]) * (pixels_per_band[j][p] - tmp_mean[j]);
if (npix == 1)
tmp_covar(i,j) = 0.0;
else
tmp_covar(i,j) = (double)(sum / (npix - 1));
}
TePDIRegion tmp_region(pols);
TEAGN_TRUE_OR_RETURN(tmp_region.Init(bands.size(), npix, tmp_mean, tmp_covar), "Unable to Init tmp_region");
regions.insert(pair<double, TePDIRegion>(area, tmp_region));
}
total_regions = regions.size();
TEAGN_TRUE_OR_RETURN(SetThreshold(acceptance_limiar, bands.size()), "Unable to SetThreshold");
TEAGN_TRUE_OR_RETURN(GenerateClusters(), "Unable to GenerateClusters");
TEAGN_TRUE_OR_RETURN(MergeClusters(), "Unable to MergeClusters");
// remap cluster values to 1 -> N
std::set<unsigned int> ulabels;
std::set<unsigned int>::iterator lit;
std::map<unsigned int, unsigned int> colormap;
for (int pols = 0; pols < total_regions; pols++)
{
TePolygon polygon(input_polygonset->operator[](pols));
// searches for the region with Id = pols
multimap<double, TePDIRegion, greater<double> >::iterator regions_it;
for (regions_it = regions.begin(); regions_it != regions.end(); ++regions_it)
if (regions_it->second.GetId() == pols)
break;
ulabels.insert(regions_it->second.GetClass());
}
unsigned int color = 1;
for (lit = ulabels.begin(); lit != ulabels.end(); ++lit)
colormap[*lit] = color++;
// paint output_raster with the correspondent classes
for (int pols = 0; pols < total_regions; pols++)
{
TePolygon polygon(input_polygonset->operator[](pols));
// this iterator "walks" in the image, on the region defined by a specific polygon
TeRaster::iteratorPoly it = input_rasters[0]->begin(polygon, TeBoxPixelIn, 0);
TeRaster::iteratorPoly it_end = input_rasters[0]->end(polygon, TeBoxPixelIn, 0);
// searches for the region with Id = pols
multimap<double, TePDIRegion, greater<double> >::iterator regions_it,
regions_tmp = regions.begin();
for (regions_it = regions.begin(); regions_it != regions.end(); ++regions_it)
if (regions_it->second.GetId() == pols)
{
regions_tmp = regions_it;
break;
}
unsigned bit_class = colormap[regions_it->second.GetClass()];
/*
// here, a set of colors for up to 81 classes, C(3, 4) = tree bands, four levels
vector<int> levels;
levels.push_back(0);
levels.push_back(50);
levels.push_back(100);
levels.push_back(150);
levels.push_back(200);
levels.push_back(255);
int change = levels.size();
vector<int> colors_R, colors_G, colors_B;
for (int c = 0, i = 0, j = 0, k = 0; c < 81; c++)
{
colors_R.push_back(levels[i]);
colors_G.push_back(levels[j]);
colors_B.push_back(levels[k]);
i++;
if (i >= change)
{
i = 0;
j++;
}
if (j >= change)
{
j = 0;
k++;
}
if (k >= change)
k = 0;
}
if (bit_class >= colors_R.size())
bit_class = 0;
double R = colors_R[bit_class],
G = colors_G[bit_class],
B = colors_B[bit_class];
*/
// paint output_raster with specific color class
while(it != it_end)
{
int i = it.currentColumn(),
j = it.currentLine();
output_raster->setElement(i, j, bit_class);
++it;
}
}
return true;
}
