/usr/include/gamera/plugins/geometry.hpp is in python-gamera-dev 3.3.3-2+deb7u1.
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* Copyright (C) 2009-2012 Christoph Dalitz
* 2010 Oliver Christen
* 2011 Christian Brandt
* 2012 David Kolanus
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#ifndef cd30112009_geometry
#define cd30112009_geometry
#include <map>
#include <set>
#include <stack>
#include <algorithm>
#include "gamera.hpp"
#include "vigra/distancetransform.hxx"
#include "vigra/seededregiongrowing.hxx"
#include "geostructs/kdtree.hpp"
#include "geostructs/delaunaytree.hpp"
#include "graph/graph.hpp"
#include "graph/graphdataderived.hpp"
#include "graph/node.hpp"
#include "plugins/contour.hpp"
#include "plugins/draw.hpp"
using namespace Gamera::Kdtree;
using namespace Gamera::Delaunaytree;
using namespace Gamera::GraphApi;
using namespace std;
namespace Gamera {
// this implementation is based on a sample program included
// in the VIGRA library by Ulrich Koethe
template<class T>
Image* voronoi_from_labeled_image(const T& src, bool white_edges=false) {
typedef typename T::value_type value_type;
typedef typename ImageFactory<T>::data_type data_type;
typedef typename ImageFactory<T>::view_type view_type;
// vigra's seeded region growing only works on greyscale images
Grey16ImageData* voronoi_data = new Grey16ImageData(src.size(), src.origin());
Grey16ImageView* voronoi = new Grey16ImageView(*voronoi_data);
size_t x,y;
value_type val, maxlabel;
map<value_type, bool> all_labels;
maxlabel = 0;
for (y=0; y<src.nrows(); ++y) {
for (x=0; x<src.ncols(); ++x) {
val = src.get(Point(x,y));
if (val > 0) {
voronoi->set(Point(x,y),val);
all_labels.insert(make_pair(val,true));
if (val > maxlabel) maxlabel = val;
} else {
voronoi->set(Point(x,y),0);
}
}
}
if (all_labels.size() <= 2) {
delete voronoi;
delete voronoi_data;
throw std::runtime_error("Black pixels must be labeled for Voronoi tesselation.");
}
FloatImageData* dist_data = new FloatImageData(src.size(), src.origin());
FloatImageView* dist = new FloatImageView(*dist_data);
try {
// The Voronoi tesselation is done by a watershed segmentation
// on the distance transform image, which is quite a bit overhead.
// The algorithm should be significantly faster when the Voronoi
// cells are computed directly similar to a distance transform.
// TODO: implement this based on VIGRA's distance transform code
vigra::distanceTransform(src_image_range(src), dest_image(*dist), 0, 2);
vigra::ArrayOfRegionStatistics<vigra::SeedRgDirectValueFunctor<float> >
statistics((size_t)maxlabel);
if (white_edges) {
vigra::seededRegionGrowing(src_image_range(*dist), src_image(*voronoi),
dest_image(*voronoi), statistics, KeepContours);
} else {
vigra::seededRegionGrowing(src_image_range(*dist), src_image(*voronoi),
dest_image(*voronoi), statistics, CompleteGrow);
}
} catch (std::exception e) {
delete dist;
delete dist_data;
delete voronoi;
delete voronoi_data;
throw;
}
// distance image no longer needed
delete dist;
delete dist_data;
// copy over result to return value
data_type* result_data = new data_type(voronoi->size(), voronoi->origin());
view_type* result = new view_type(*result_data);
for (y=0; y<voronoi->nrows(); ++y) {
for (x=0; x<voronoi->ncols(); ++x) {
result->set(Point(x,y),(value_type)voronoi->get(Point(x,y)));
}
}
// greyscale image no longer needed
delete voronoi;
delete voronoi_data;
return result;
}
template<class T>
void voronoi_from_points(T& src, const PointVector* points, IntVector* labels) {
// some plausi checks
if (points->empty())
throw std::runtime_error("points must not be empty.");
if (points->size() != labels->size())
throw std::runtime_error("Number of points must match the number of labels.");
size_t i,x,y;
// build kd-tree from points
KdNodeVector nodes,neighbors;
CoordPoint p(2);
for (i=0; i<points->size(); i++) {
p[0] = (*points)[i].x();
p[1] = (*points)[i].y();
KdNode n(p);
n.data = &((*labels)[i]);
nodes.push_back(n);
}
KdTree tree(&nodes);
// label all pixels with nearest neighbor label
for (y=0; y<src.nrows(); ++y) {
for (x=0; x<src.ncols(); ++x) {
if (src.get(Point(x,y)) == 0) {
p[0] = x; p[1] = y;
tree.k_nearest_neighbors(p, 1, &neighbors);
src.set(Point(x,y),*((int*)(neighbors[0].data)));
}
}
}
}
// returns list of neighboring label pairs
template<class T>
PyObject* labeled_region_neighbors(const T& src, bool eight_connectivity=true) {
size_t x,y,max_x,max_y;
typedef typename T::value_type value_type;
max_x = src.ncols()-1;
max_y = src.nrows()-1;
// map for storing neighborship relations; to avoid duplicates,
// we store for each label only *smaller* neighboring labels
// note that we must use 'int' insetad of 'value_type' because
// some versions of gcc do not like nested templates
typedef set<value_type> set_type;
typedef map<value_type,set_type> map_type;
map_type neighbors;
// check bulk of image
value_type label1,label2;
//set<value_type> emptyset;
set_type emptyset;
for (y=0; y<max_y; ++y) {
for (x=0; x<max_x; ++x) {
label1 = src.get(Point(x,y));
label2 = src.get(Point(x+1,y));
if (label1 > label2) {
if (neighbors.find(label1) == neighbors.end())
neighbors[label1] = emptyset;
neighbors[label1].insert(label2);
}
else if (label2 > label1) {
if (neighbors.find(label2) == neighbors.end())
neighbors[label2] = emptyset;
neighbors[label2].insert(label1);
}
label2 = src.get(Point(x,y+1));
if (label1 > label2) {
if (neighbors.find(label1) == neighbors.end())
neighbors[label1] = emptyset;
neighbors[label1].insert(label2);
}
else if (label2 > label1) {
if (neighbors.find(label2) == neighbors.end())
neighbors[label2] = emptyset;
neighbors[label2].insert(label1);
}
if (eight_connectivity) {
label2 = src.get(Point(x+1,y+1));
if (label1 > label2) {
if (neighbors.find(label1) == neighbors.end())
neighbors[label1] = emptyset;
neighbors[label1].insert(label2);
}
else if (label2 > label1) {
if (neighbors.find(label2) == neighbors.end())
neighbors[label2] = emptyset;
neighbors[label2].insert(label1);
}
}
}
}
// check last row
for (x=0; x<max_x; ++x) {
label1 = src.get(Point(x,max_y));
label2 = src.get(Point(x+1,max_y));
if (label1 > label2) {
if (neighbors.find(label1) == neighbors.end())
neighbors[label1] = emptyset;
neighbors[label1].insert(label2);
}
else if (label2 > label1) {
if (neighbors.find(label2) == neighbors.end())
neighbors[label2] = emptyset;
neighbors[label2].insert(label1);
}
}
// check last column
for (y=0; y<max_y; ++y) {
label1 = src.get(Point(max_x,y));
label2 = src.get(Point(max_x,y+1));
if (label1 > label2) {
if (neighbors.find(label1) == neighbors.end())
neighbors[label1] = emptyset;
neighbors[label1].insert(label2);
}
else if (label2 > label1) {
if (neighbors.find(label2) == neighbors.end())
neighbors[label2] = emptyset;
neighbors[label2].insert(label1);
}
}
//printf("emptyset.size(): %i\n", emptyset.size());
// copy result over to return value
PyObject *retval, *entry, *entry1, *entry2;
retval = PyList_New(0);
typename map_type::iterator it1;
typename set_type::iterator it2;
for (it1=neighbors.begin(); it1!=neighbors.end(); it1++) {
entry1 = Py_BuildValue("i", (int)it1->first);
//printf("Neighbors of %i:", (int)it1->first);
for (it2=it1->second.begin(); it2!=it1->second.end(); it2++) {
// beware that PyList_SetItem 'steals' a reference,
// while PyList_append increases the reference
entry = PyList_New(2);
Py_INCREF(entry1);
PyList_SetItem(entry, 0, entry1);
entry2 = Py_BuildValue("i", (int)*it2);
//printf(" %i", (int)*it2);
PyList_SetItem(entry, 1, entry2);
PyList_Append(retval, entry);
Py_DECREF(entry);
}
//printf("\n");
Py_DECREF(entry1);
}
return retval;
}
//-----------------------------------------------------------------------
// functions for Delaunay triangulation
//-----------------------------------------------------------------------
void delaunay_from_points_cpp(PointVector *pv, IntVector *lv, std::map<int,std::set<int> > *result) {
// some plausi checks
if (pv->empty()) {
throw std::runtime_error("No points for triangulation given.");
}
if (pv->size() < 3) {
throw std::runtime_error("At least three points are required.");
}
if (pv->size() != lv->size()) {
throw std::runtime_error("Number of points must match the number of labels.");
}
DelaunayTree dt;
PointVector::iterator pv_it;
IntVector::iterator lv_it;
std::vector<Vertex*> vertices;
std::vector<Vertex*>::iterator it;
result->clear();
pv_it = pv->begin();
lv_it = lv->begin();
int x, y;
while(pv_it != pv->end() && lv_it != lv->end()) {
x = (*pv_it).x();
y = (*pv_it).y();
vertices.push_back(new Vertex(x, y, (*lv_it)));
++pv_it;
++lv_it;
}
random_shuffle(vertices.begin(), vertices.end());
dt.addVertices(&vertices);
dt.neighboringLabels(result);
for(it = vertices.begin() ; it != vertices.end() ; ++it) {
delete *it;
}
}
PyObject* delaunay_from_points(PointVector *pv, IntVector *lv) {
PyObject *list, *entry, *label1, *label2;
std::map<int,std::set<int> > neighbors;
std::map<int,std::set<int> >::iterator nit1;
std::set<int>::iterator nit2;
delaunay_from_points_cpp(pv, lv, &neighbors);
list = PyList_New(0);
for (nit1=neighbors.begin(); nit1!=neighbors.end(); ++nit1) {
for (nit2=nit1->second.begin(); nit2!=nit1->second.end(); nit2++) {
entry = PyList_New(2);
label1 = Py_BuildValue("i", nit1->first);
label2 = Py_BuildValue("i", *nit2);
PyList_SetItem(entry, 0, label1);
PyList_SetItem(entry, 1, label2);
PyList_Append(list, entry);
Py_DECREF(entry);
}
}
return list;
}
//-----------------------------------------------------------------------
// functions for graph coloring of Cc's with different colors
//-----------------------------------------------------------------------
typedef std::map<unsigned int, Image*> LabelCcMap;
template<class T>
Graph *graph_from_ccs(T &image, ImageVector &ccs, int method) {
Graph *graph = new Graph(FLAG_UNDIRECTED);
graph->make_singly_connected();
PointVector *pv = new PointVector();
IntVector *iv = new IntVector();
ImageVector::iterator iter;
if( method == 0 || method == 1 ) {
if( method == 0 ) {
// method == 0 --> from the CC center points
for( iter = ccs.begin(); iter != ccs.end(); iter++) {
Cc* cc = static_cast<Cc*>((*iter).first);
pv->push_back( cc->center() );
iv->push_back( cc->label() );
}
}
else if( method == 1) {
// method == 1 --> from a 20 percent sample of the contour points
for( iter = ccs.begin(); iter != ccs.end(); iter++) {
Cc* cc = static_cast<Cc*>((*iter).first);
PointVector *cc_pv = contour_samplepoints(*cc, 20);
PointVector::iterator point_vec_iter;
for( point_vec_iter = cc_pv->begin(); point_vec_iter != cc_pv->end(); point_vec_iter++ ) {
pv->push_back(*point_vec_iter);
iv->push_back(cc->label());
}
delete cc_pv;
}
}
// Build the graph
std::map<int,std::set<int> > neighbors;
std::map<int,std::set<int> >::iterator nit1;
std::set<int>::iterator nit2;
delaunay_from_points_cpp(pv, iv, &neighbors);
for (nit1=neighbors.begin(); nit1!=neighbors.end(); ++nit1) {
for (nit2=nit1->second.begin(); nit2!=nit1->second.end(); nit2++) {
GraphDataLong* a_p = new GraphDataLong(nit1->first);
GraphDataLong* b_p = new GraphDataLong(*nit2);
bool del_a = !graph->add_node(a_p);
bool del_b = !graph->add_node(b_p);
graph->add_edge(a_p, b_p);
if(del_a)
delete a_p;
if(del_b)
delete b_p;
}
}
}
else if( method == 2 ) {
// method == 2 --> from the exact area Voronoi diagram
typedef typename ImageFactory<T>::view_type view_type;
Image *voronoi = voronoi_from_labeled_image(image);
PyObject *labelpairs = labeled_region_neighbors( *((view_type*) voronoi) );
for (int i = 0; i < PyList_Size(labelpairs); i++) {
PyObject *adj_list = PyList_GetItem(labelpairs, i);
PyObject *region1 = PyList_GetItem(adj_list, 0);
PyObject *region2 = PyList_GetItem(adj_list, 1);
GraphDataLong* a_p = new GraphDataLong(PyInt_AsLong(region1));
GraphDataLong* b_p = new GraphDataLong(PyInt_AsLong(region2));
bool del_a = !graph->add_node(a_p);
bool del_b = !graph->add_node(b_p);
graph->add_edge(a_p, b_p);
if(del_a)
delete a_p;
if(del_b)
delete b_p;
}
delete voronoi->data();
delete voronoi;
Py_DECREF(labelpairs);
}
else {
throw std::runtime_error("Unknown method for construction the neighborhood graph");
}
delete pv;
delete iv;
return graph;
}
template<class T>
RGBImageView* graph_color_ccs(T &image, ImageVector &ccs, PyObject *colors, int method) {
Graph *graph = NULL;
std::vector<RGBPixel*> RGBColors;
// check input parameters
if( ccs.size() == 0 ) {
throw std::runtime_error("graph_color_ccs: no CCs given.");
}
if( !PyList_Check(colors) ) {
throw std::runtime_error("graph_color_ccs: colors is no list");
}
if( PyList_Size(colors) < 6 ) {
throw std::runtime_error("graph_color_ccs: coloring algorithm only works "
"with more than five colors");
}
// extract the colors
for( int i = 0; i < PyList_Size(colors); i++) {
PyObject *Py_RGBPixel = PyList_GetItem(colors, i);
RGBPixel *RGBPixel = ((RGBPixelObject*) Py_RGBPixel )->m_x;
RGBColors.push_back(RGBPixel);
}
// build the graph from the given ccs
graph = graph_from_ccs(image, ccs, method);
// volor the graph
graph->colorize( PyList_Size(colors) );
// Create the return image
// Ccs not passed to the function are set black in the result
typedef TypeIdImageFactory<RGB, DENSE> RGBViewFactory;
RGBViewFactory::image_type *coloredImage =
RGBViewFactory::create(image.origin(), image.dim());
int label;
for( size_t y = 0; y < image.nrows(); y++) {
for( size_t x = 0; x < image.ncols(); x++ ) {
label = image.get(Point(x,y));
if( label != 0 ) {
try {
GraphDataLong d(label);
Node* n = graph->get_node(&d);
unsigned int c = graph->get_color(n);
coloredImage->set(Point(x,y), *RGBColors[c]);
}
catch( std::runtime_error runtimeError ) {
coloredImage->set(Point(x,y), RGBPixel(0,0,0));
}
}
}
}
NodePtrIterator* it = graph->get_nodes();
Node* n;
while((n = it->next()) != NULL) {
delete dynamic_cast<GraphDataLong*>(n->_value);
}
delete it;
delete graph;
return coloredImage;
}
//------------------------------------------------------------------
// convex hull computation with Graham's scan algorithm.
// See Cormen et al.: Introduction to Algorithms. 2nd ed., p. 949
//------------------------------------------------------------------
inline bool greater_distance(const Point& origin, const Point& p1, const Point& p2) {
double dx2 = (double)p2.x() - origin.x();
double dx1 = (double)p1.x() - origin.x();
double dy2 = (double)p2.y() - origin.y();
double dy1 = (double)p1.y() - origin.y();
if (dy1*dy1+dx1*dx1 > dy2*dy2+dx2*dx2) {
return true;
}
return false;
}
// positive when p0p1 clockwise oriented compared to p0p2
// zero when all points collinear
inline double clockwise_orientation(const Point& p0, const Point& p1, const Point& p2) {
return ((double)p1.x() - p0.x())*((double)p2.y() - p0.y()) -
((double)p2.x() - p0.x())*((double)p1.y() - p0.y());
}
inline double polar_angle(Point center, Point p2) {
double dx = double(p2.x()) - center.x();
double dy = double(p2.y()) - center.y();
return atan2(dy, dx);
};
// see Cormen et al.: Introduction to Algorithms.
// 2nd ed., MIT Press, p. 949, 2001
PointVector* convex_hull_from_points(PointVector *points) {
//get leftmost and top point and save it in (*points)[0]
size_t min_x = points->at(0).x();
size_t min_y = points->at(0).y();
size_t min_i = 0;
size_t i;
for(i=0; i < points->size(); i++) {
if (points->at(i).x() < min_x) {
min_x = points->at(i).x();
min_y = points->at(i).y();
min_i = i;
} else if (points->at(i).x() < min_x && points->at(i).y() < min_y) {
min_x = points->at(i).x();
min_y = points->at(i).y();
min_i = i;
}
}
std::swap( points->at(0), points->at(min_i));
//sort by polar in polarmap. If more than one point,
//remove all but the one farthest from origin
Point origin = points->at(0);
std::map<double, Point> stack_polarangle;
std::map<double, Point>::iterator found;
double polarangle;
Point p;
for(PointVector::iterator it = points->begin()+1; it != points->end();it++) {
p = *it;
polarangle = polar_angle(origin, p);
found = stack_polarangle.find(polarangle);
//use nearest
if(found == stack_polarangle.end()){
stack_polarangle[polarangle] = p;
}
else if(greater_distance(origin, p, found->second)) {
stack_polarangle[polarangle] = p;
}
}
// start with graham scan
PointVector* retVector = new PointVector;
std::map<double, Point>::iterator pointIt;
pointIt = stack_polarangle.begin();
retVector->push_back(origin); // push point[0]
retVector->push_back(pointIt->second); // push point[1]
pointIt++;
retVector->push_back(pointIt->second); // push point[2]
pointIt++;
//pointIt starts at point[3]
for( ; pointIt != stack_polarangle.end(); pointIt++) {
p = pointIt->second;
while(retVector->size() > 2 && clockwise_orientation(*(retVector->end()-2),*(retVector->end()-1), p) <= 0.0) {
retVector->pop_back();
}
retVector->push_back(p);
}
return retVector;
}
template<class T>
PointVector* convex_hull_as_points(const T& src) {
PointVector *contour_points = new PointVector();
PointVector::iterator found;
FloatVector *left = contour_left(src);
FloatVector *right = contour_right(src);
FloatVector::iterator it;
size_t y;
for(it = left->begin(), y=0; it != left->end() ; it++, y++) {
if( *it != std::numeric_limits<double>::infinity() ) {
contour_points->push_back(Point((int)*it,y));
}
}
for(it = right->begin(), y=0; it != right->end() ; it++, y++) {
if( *it != std::numeric_limits<double>::infinity() ) {
contour_points->push_back(Point((int)src.ncols()-*it,y));
}
}
PointVector *output = convex_hull_from_points(contour_points);
delete left;
delete right;
delete contour_points;
return output;
}
template<class T>
Image* convex_hull_as_image(const T& src, bool filled) {
typedef typename T::value_type value_type;
typedef typename ImageFactory<OneBitImageView>::view_type view_type;
OneBitImageData* res_data = new OneBitImageData(src.size(),src.origin());
OneBitImageView* res = new OneBitImageView(*res_data,src.origin(),src.size());
PointVector* hullpoints = convex_hull_as_points(src);
for (size_t i=1; i< hullpoints->size(); i++)
draw_line(*res,hullpoints->at(i-1),hullpoints->at(i),black(*res));
draw_line(*res,hullpoints->back(),hullpoints->front(),black(*res));
delete hullpoints;
if (filled) {
size_t x,y,from,to;
for (y=0; y<res->nrows(); y++) {
from = to = res->ncols();
from = 0;
while (from < res->ncols() && is_white(res->get(Point(from,y))))
from++;
if (from >= res->ncols()-1) continue;
to = res->ncols()-1;
while (to > 0 && is_white(res->get(Point(to,y))))
to--;
for (x=from+1; x<to; x++)
res->set(Point(x,y),black(*res));
}
}
return res;
}
// based upon a sample program kindly provided by Daveed Vandevoorde
template<class T>
Rect* max_empty_rect(const T& src) {
size_t x,y,open_width,x0;
unsigned int w0,area,best_area;
std::vector<unsigned int> c(src.ncols()+1,0);
std::stack<unsigned int> s;
Point best_ul(0,0);
Point best_lr(0,0);
best_area = 0;
for (y=0; y<src.nrows(); ++y) {
open_width = 0;
// update cache
for (x=0; x<src.ncols(); ++x) {
if (is_black(src.get(Point(x,y)))) {
c[x] = 0;
} else {
++c[x];
}
}
for (x=0; x<=src.ncols(); ++x) {
if (c[x]>open_width) { // open new rectangle?
s.push(x);
s.push(open_width);
open_width = c[x];
} // "else" optional here
else if (c[x]<open_width) { // close rectangle(s)?
do {
w0 = s.top(); s.pop();
x0 = s.top(); s.pop();
area = open_width*(x-x0);
if (area>best_area) {
best_area = area;
best_ul = Point(x0, y-open_width+1);
best_lr = Point(x-1, y);
}
open_width = w0;
} while (c[x]<open_width);
open_width = c[x];
if (open_width!=0) {
s.push(x0);
s.push(w0);
}
}
}
}
if (is_black(src.get(best_lr))) {
throw std::runtime_error("max_empty_rect: image has no white pixels.");
}
Rect* result = new Rect(best_ul,best_lr);
return result;
}
} // namespace Gamera
#endif
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