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//
// The original code was written by
// Marius Muja
// and later modified and prepared
// for integration into OpenCV by
// Antonella Cascitelli,
// Marco Di Stefano and
// Stefano Fabri
// from Univ. of Rome
//
#include "precomp.hpp"
#include "opencv2/opencv_modules.hpp"
#ifdef HAVE_OPENCV_HIGHGUI
# include "opencv2/highgui/highgui.hpp"
#endif
#include <iostream>
#include <queue>
namespace cv
{
typedef std::pair<int,int> coordinate_t;
typedef float orientation_t;
typedef std::vector<coordinate_t> template_coords_t;
typedef std::vector<orientation_t> template_orientations_t;
typedef std::pair<Point, float> location_scale_t;
class ChamferMatcher
{
private:
class Matching;
int max_matches_;
float min_match_distance_;
///////////////////////// Image iterators ////////////////////////////
class ImageIterator
{
public:
virtual ~ImageIterator() {}
virtual bool hasNext() const = 0;
virtual location_scale_t next() = 0;
};
class ImageRange
{
public:
virtual ImageIterator* iterator() const = 0;
virtual ~ImageRange() {}
};
// Sliding window
class SlidingWindowImageRange : public ImageRange
{
int width_;
int height_;
int x_step_;
int y_step_;
int scales_;
float min_scale_;
float max_scale_;
public:
SlidingWindowImageRange(int width, int height, int x_step = 3, int y_step = 3, int _scales = 5, float min_scale = 0.6, float max_scale = 1.6) :
width_(width), height_(height), x_step_(x_step),y_step_(y_step), scales_(_scales), min_scale_(min_scale), max_scale_(max_scale)
{
}
ImageIterator* iterator() const;
};
class LocationImageRange : public ImageRange
{
const std::vector<Point>& locations_;
int scales_;
float min_scale_;
float max_scale_;
LocationImageRange(const LocationImageRange&);
LocationImageRange& operator=(const LocationImageRange&);
public:
LocationImageRange(const std::vector<Point>& locations, int _scales = 5, float min_scale = 0.6, float max_scale = 1.6) :
locations_(locations), scales_(_scales), min_scale_(min_scale), max_scale_(max_scale)
{
}
ImageIterator* iterator() const
{
return new LocationImageIterator(locations_, scales_, min_scale_, max_scale_);
}
};
class LocationScaleImageRange : public ImageRange
{
const std::vector<Point>& locations_;
const std::vector<float>& scales_;
LocationScaleImageRange(const LocationScaleImageRange&);
LocationScaleImageRange& operator=(const LocationScaleImageRange&);
public:
LocationScaleImageRange(const std::vector<Point>& locations, const std::vector<float>& _scales) :
locations_(locations), scales_(_scales)
{
assert(locations.size()==_scales.size());
}
ImageIterator* iterator() const
{
return new LocationScaleImageIterator(locations_, scales_);
}
};
public:
/**
* Class that represents a template for chamfer matching.
*/
class Template
{
friend class ChamferMatcher::Matching;
friend class ChamferMatcher;
public:
std::vector<Template*> scaled_templates;
std::vector<int> addr;
int addr_width;
float scale;
template_coords_t coords;
template_orientations_t orientations;
Size size;
Point center;
public:
Template() : addr_width(-1)
{
}
Template(Mat& edge_image, float scale_ = 1);
~Template()
{
for (size_t i=0;i<scaled_templates.size();++i) {
delete scaled_templates[i];
}
scaled_templates.clear();
coords.clear();
orientations.clear();
}
void show() const;
private:
/**
* Resizes a template
*
* @param scale Scale to be resized to
*/
Template* rescale(float scale);
std::vector<int>& getTemplateAddresses(int width);
};
/**
* Used to represent a matching result.
*/
class Match
{
public:
float cost;
Point offset;
const Template* tpl;
};
typedef std::vector<Match> Matches;
private:
/**
* Implements the chamfer matching algorithm on images taking into account both distance from
* the template pixels to the nearest pixels and orientation alignment between template and image
* contours.
*/
class Matching
{
float truncate_;
bool use_orientation_;
std::vector<Template*> templates;
public:
Matching(bool use_orientation = true, float _truncate = 10) : truncate_(_truncate), use_orientation_(use_orientation)
{
}
~Matching()
{
for (size_t i = 0; i<templates.size(); i++) {
delete templates[i];
}
}
/**
* Add a template to the detector from an edge image.
* @param templ An edge image
*/
void addTemplateFromImage(Mat& templ, float scale = 1.0);
/**
* Run matching using an edge image.
* @param edge_img Edge image
* @return a match object
*/
ChamferMatcher::Matches* matchEdgeImage(Mat& edge_img, const ImageRange& range, float orientation_weight = 0.5, int max_matches = 20, float min_match_distance = 10.0);
void addTemplate(Template& template_);
private:
float orientation_diff(float o1, float o2)
{
return fabs(o1-o2);
}
/**
* Computes the chamfer matching cost for one position in the target image.
* @param offset Offset where to compute cost
* @param dist_img Distance transform image.
* @param orientation_img Orientation image.
* @param tpl Template
* @param templ_orientations Orientations of the target points.
* @return matching result
*/
ChamferMatcher::Match* localChamferDistance(Point offset, Mat& dist_img, Mat& orientation_img, Template* tpl, float orientation_weight);
private:
/**
* Matches all templates.
* @param dist_img Distance transform image.
* @param orientation_img Orientation image.
*/
ChamferMatcher::Matches* matchTemplates(Mat& dist_img, Mat& orientation_img, const ImageRange& range, float orientation_weight);
void computeDistanceTransform(Mat& edges_img, Mat& dist_img, Mat& annotate_img, float truncate_dt, float a, float b);
void computeEdgeOrientations(Mat& edge_img, Mat& orientation_img);
void fillNonContourOrientations(Mat& annotated_img, Mat& orientation_img);
public:
/**
* Finds a contour in an edge image. The original image is altered by removing the found contour.
* @param templ_img Edge image
* @param coords Coordinates forming the contour.
* @return True while a contour is still found in the image.
*/
static bool findContour(Mat& templ_img, template_coords_t& coords);
/**
* Computes contour points orientations using the approach from:
*
* Matas, Shao and Kittler - Estimation of Curvature and Tangent Direction by
* Median Filtered Differencing
*
* @param coords Contour points
* @param orientations Contour points orientations
*/
static void findContourOrientations(const template_coords_t& coords, template_orientations_t& orientations);
/**
* Computes the angle of a line segment.
*
* @param a One end of the line segment
* @param b The other end.
* @param dx
* @param dy
* @return Angle in radians.
*/
static float getAngle(coordinate_t a, coordinate_t b, int& dx, int& dy);
/**
* Finds a point in the image from which to start contour following.
* @param templ_img
* @param p
* @return
*/
static bool findFirstContourPoint(Mat& templ_img, coordinate_t& p);
/**
* Method that extracts a single continuous contour from an image given a starting point.
* When it extracts the contour it tries to maintain the same direction (at a T-join for example).
*
* @param templ_
* @param coords
* @param direction
*/
static void followContour(Mat& templ_img, template_coords_t& coords, int direction);
};
class LocationImageIterator : public ImageIterator
{
const std::vector<Point>& locations_;
size_t iter_;
int scales_;
float min_scale_;
float max_scale_;
float scale_;
float scale_step_;
int scale_cnt_;
bool has_next_;
LocationImageIterator(const LocationImageIterator&);
LocationImageIterator& operator=(const LocationImageIterator&);
public:
LocationImageIterator(const std::vector<Point>& locations, int _scales, float min_scale, float max_scale);
bool hasNext() const {
return has_next_;
}
location_scale_t next();
};
class LocationScaleImageIterator : public ImageIterator
{
const std::vector<Point>& locations_;
const std::vector<float>& scales_;
size_t iter_;
bool has_next_;
LocationScaleImageIterator(const LocationScaleImageIterator&);
LocationScaleImageIterator& operator=(const LocationScaleImageIterator&);
public:
LocationScaleImageIterator(const std::vector<Point>& locations, const std::vector<float>& _scales) :
locations_(locations), scales_(_scales)
{
assert(locations.size()==_scales.size());
reset();
}
void reset()
{
iter_ = 0;
has_next_ = (locations_.size()==0 ? false : true);
}
bool hasNext() const {
return has_next_;
}
location_scale_t next();
};
class SlidingWindowImageIterator : public ImageIterator
{
int x_;
int y_;
float scale_;
float scale_step_;
int scale_cnt_;
bool has_next_;
int width_;
int height_;
int x_step_;
int y_step_;
int scales_;
float min_scale_;
float max_scale_;
public:
SlidingWindowImageIterator(int width, int height, int x_step, int y_step, int scales, float min_scale, float max_scale);
bool hasNext() const {
return has_next_;
}
location_scale_t next();
};
int count;
Matches matches;
int pad_x;
int pad_y;
int scales;
float minScale;
float maxScale;
float orientation_weight;
float truncate;
Matching * chamfer_;
public:
ChamferMatcher(int _max_matches = 20, float _min_match_distance = 1.0, int _pad_x = 3,
int _pad_y = 3, int _scales = 5, float _minScale = 0.6, float _maxScale = 1.6,
float _orientation_weight = 0.5, float _truncate = 20)
{
max_matches_ = _max_matches;
min_match_distance_ = _min_match_distance;
pad_x = _pad_x;
pad_y = _pad_y;
scales = _scales;
minScale = _minScale;
maxScale = _maxScale;
orientation_weight = _orientation_weight;
truncate = _truncate;
count = 0;
matches.resize(max_matches_);
chamfer_ = new Matching(true);
}
void showMatch(Mat& img, int index = 0);
void showMatch(Mat& img, Match match_);
const Matches& matching(Template&, Mat&);
private:
void addMatch(float cost, Point offset, const Template* tpl);
};
///////////////////// implementation ///////////////////////////
ChamferMatcher::SlidingWindowImageIterator::SlidingWindowImageIterator( int width,
int height,
int x_step = 3,
int y_step = 3,
int _scales = 5,
float min_scale = 0.6,
float max_scale = 1.6) :
width_(width),
height_(height),
x_step_(x_step),
y_step_(y_step),
scales_(_scales),
min_scale_(min_scale),
max_scale_(max_scale)
{
x_ = 0;
y_ = 0;
scale_cnt_ = 0;
scale_ = min_scale_;
has_next_ = true;
scale_step_ = (max_scale_-min_scale_)/scales_;
}
location_scale_t ChamferMatcher::SlidingWindowImageIterator::next()
{
location_scale_t next_val = std::make_pair(Point(x_,y_),scale_);
x_ += x_step_;
if (x_ >= width_) {
x_ = 0;
y_ += y_step_;
if (y_ >= height_) {
y_ = 0;
scale_ += scale_step_;
scale_cnt_++;
if (scale_cnt_ == scales_) {
has_next_ = false;
scale_cnt_ = 0;
scale_ = min_scale_;
}
}
}
return next_val;
}
ChamferMatcher::ImageIterator* ChamferMatcher::SlidingWindowImageRange::iterator() const
{
return new SlidingWindowImageIterator(width_, height_, x_step_, y_step_, scales_, min_scale_, max_scale_);
}
ChamferMatcher::LocationImageIterator::LocationImageIterator(const std::vector<Point>& locations,
int _scales = 5,
float min_scale = 0.6,
float max_scale = 1.6) :
locations_(locations),
scales_(_scales),
min_scale_(min_scale),
max_scale_(max_scale)
{
iter_ = 0;
scale_cnt_ = 0;
scale_ = min_scale_;
has_next_ = (locations_.size()==0 ? false : true);
scale_step_ = (max_scale_-min_scale_)/scales_;
}
location_scale_t ChamferMatcher::LocationImageIterator:: next()
{
location_scale_t next_val = std::make_pair(locations_[iter_],scale_);
iter_ ++;
if (iter_==locations_.size()) {
iter_ = 0;
scale_ += scale_step_;
scale_cnt_++;
if (scale_cnt_ == scales_) {
has_next_ = false;
scale_cnt_ = 0;
scale_ = min_scale_;
}
}
return next_val;
}
location_scale_t ChamferMatcher::LocationScaleImageIterator::next()
{
location_scale_t next_val = std::make_pair(locations_[iter_],scales_[iter_]);
iter_ ++;
if (iter_==locations_.size()) {
iter_ = 0;
has_next_ = false;
}
return next_val;
}
bool ChamferMatcher::Matching::findFirstContourPoint(Mat& templ_img, coordinate_t& p)
{
for (int y=0;y<templ_img.rows;++y) {
for (int x=0;x<templ_img.cols;++x) {
if (templ_img.at<uchar>(y,x)!=0) {
p.first = x;
p.second = y;
return true;
}
}
}
return false;
}
void ChamferMatcher::Matching::followContour(Mat& templ_img, template_coords_t& coords, int direction = -1)
{
const int dir[][2] = { {-1,-1}, {-1,0}, {-1,1}, {0,1}, {1,1}, {1,0}, {1,-1}, {0,-1} };
coordinate_t next;
unsigned char ptr;
assert (direction==-1 || !coords.empty());
coordinate_t crt = coords.back();
// mark the current pixel as visited
templ_img.at<uchar>(crt.second,crt.first) = 0;
if (direction==-1) {
for (int j = 0; j<7; ++j) {
next.first = crt.first + dir[j][1];
next.second = crt.second + dir[j][0];
if (next.first >= 0 && next.first < templ_img.cols &&
next.second >= 0 && next.second < templ_img.rows){
ptr = templ_img.at<uchar>(next.second, next.first);
if (ptr!=0) {
coords.push_back(next);
followContour(templ_img, coords,j);
// try to continue contour in the other direction
reverse(coords.begin(), coords.end());
followContour(templ_img, coords, (j+4)%8);
break;
}
}
}
}
else {
int k = direction;
int k_cost = 3;
next.first = crt.first + dir[k][1];
next.second = crt.second + dir[k][0];
if (next.first >= 0 && next.first < templ_img.cols &&
next.second >= 0 && next.second < templ_img.rows){
ptr = templ_img.at<uchar>(next.second, next.first);
if (ptr!=0) {
k_cost = std::abs(dir[k][1]) + std::abs(dir[k][0]);
}
int p = k;
int n = k;
for (int j = 0 ;j<3; ++j) {
p = (p + 7) % 8;
n = (n + 1) % 8;
next.first = crt.first + dir[p][1];
next.second = crt.second + dir[p][0];
if (next.first >= 0 && next.first < templ_img.cols &&
next.second >= 0 && next.second < templ_img.rows){
ptr = templ_img.at<uchar>(next.second, next.first);
if (ptr!=0) {
int p_cost = std::abs(dir[p][1]) + std::abs(dir[p][0]);
if (p_cost<k_cost) {
k_cost = p_cost;
k = p;
}
}
next.first = crt.first + dir[n][1];
next.second = crt.second + dir[n][0];
if (next.first >= 0 && next.first < templ_img.cols &&
next.second >= 0 && next.second < templ_img.rows){
ptr = templ_img.at<uchar>(next.second, next.first);
if (ptr!=0) {
int n_cost = std::abs(dir[n][1]) + std::abs(dir[n][0]);
if (n_cost<k_cost) {
k_cost = n_cost;
k = n;
}
}
}
}
}
if (k_cost!=3) {
next.first = crt.first + dir[k][1];
next.second = crt.second + dir[k][0];
if (next.first >= 0 && next.first < templ_img.cols &&
next.second >= 0 && next.second < templ_img.rows) {
coords.push_back(next);
followContour(templ_img, coords, k);
}
}
}
}
}
bool ChamferMatcher::Matching::findContour(Mat& templ_img, template_coords_t& coords)
{
coordinate_t start_point;
bool found = findFirstContourPoint(templ_img,start_point);
if (found) {
coords.push_back(start_point);
followContour(templ_img, coords);
return true;
}
return false;
}
float ChamferMatcher::Matching::getAngle(coordinate_t a, coordinate_t b, int& dx, int& dy)
{
dx = b.first-a.first;
dy = -(b.second-a.second); // in image coordinated Y axis points downward
float angle = atan2((float)dy,(float)dx);
if (angle<0) {
angle+=(float)CV_PI;
}
return angle;
}
void ChamferMatcher::Matching::findContourOrientations(const template_coords_t& coords, template_orientations_t& orientations)
{
const int M = 5;
int coords_size = (int)coords.size();
std::vector<float> angles(2*M);
orientations.insert(orientations.begin(), coords_size, float(-3*CV_PI)); // mark as invalid in the beginning
if (coords_size<2*M+1) { // if contour not long enough to estimate orientations, abort
return;
}
for (int i=M;i<coords_size-M;++i) {
coordinate_t crt = coords[i];
coordinate_t other;
int k = 0;
int dx, dy;
// compute previous M angles
for (int j=M;j>0;--j) {
other = coords[i-j];
angles[k++] = getAngle(other,crt, dx, dy);
}
// compute next M angles
for (int j=1;j<=M;++j) {
other = coords[i+j];
angles[k++] = getAngle(crt, other, dx, dy);
}
// get the middle two angles
std::nth_element(angles.begin(), angles.begin()+M-1, angles.end());
std::nth_element(angles.begin()+M-1, angles.begin()+M, angles.end());
// sort(angles.begin(), angles.end());
// average them to compute tangent
orientations[i] = (angles[M-1]+angles[M])/2;
}
}
//////////////////////// Template /////////////////////////////////////
ChamferMatcher::Template::Template(Mat& edge_image, float scale_) : addr_width(-1), scale(scale_)
{
template_coords_t local_coords;
template_orientations_t local_orientations;
while (ChamferMatcher::Matching::findContour(edge_image, local_coords)) {
ChamferMatcher::Matching::findContourOrientations(local_coords, local_orientations);
coords.insert(coords.end(), local_coords.begin(), local_coords.end());
orientations.insert(orientations.end(), local_orientations.begin(), local_orientations.end());
local_coords.clear();
local_orientations.clear();
}
size = edge_image.size();
Point min, max;
min.x = size.width;
min.y = size.height;
max.x = 0;
max.y = 0;
center = Point(0,0);
for (size_t i=0;i<coords.size();++i) {
center.x += coords[i].first;
center.y += coords[i].second;
if (min.x>coords[i].first) min.x = coords[i].first;
if (min.y>coords[i].second) min.y = coords[i].second;
if (max.x<coords[i].first) max.x = coords[i].first;
if (max.y<coords[i].second) max.y = coords[i].second;
}
size.width = max.x - min.x;
size.height = max.y - min.y;
int coords_size = (int)coords.size();
center.x /= MAX(coords_size, 1);
center.y /= MAX(coords_size, 1);
for (int i=0;i<coords_size;++i) {
coords[i].first -= center.x;
coords[i].second -= center.y;
}
}
std::vector<int>& ChamferMatcher::Template::getTemplateAddresses(int width)
{
if (addr_width!=width) {
addr.resize(coords.size());
addr_width = width;
for (size_t i=0; i<coords.size();++i) {
addr[i] = coords[i].second*width+coords[i].first;
}
}
return addr;
}
/**
* Resizes a template
*
* @param scale Scale to be resized to
*/
ChamferMatcher::Template* ChamferMatcher::Template::rescale(float new_scale)
{
if (fabs(scale-new_scale)<1e-6) return this;
for (size_t i=0;i<scaled_templates.size();++i) {
if (fabs(scaled_templates[i]->scale-new_scale)<1e-6) {
return scaled_templates[i];
}
}
float scale_factor = new_scale/scale;
Template* tpl = new Template();
tpl->scale = new_scale;
tpl->center.x = int(center.x*scale_factor+0.5);
tpl->center.y = int(center.y*scale_factor+0.5);
tpl->size.width = int(size.width*scale_factor+0.5);
tpl->size.height = int(size.height*scale_factor+0.5);
tpl->coords.resize(coords.size());
tpl->orientations.resize(orientations.size());
for (size_t i=0;i<coords.size();++i) {
tpl->coords[i].first = int(coords[i].first*scale_factor+0.5);
tpl->coords[i].second = int(coords[i].second*scale_factor+0.5);
tpl->orientations[i] = orientations[i];
}
scaled_templates.push_back(tpl);
return tpl;
}
void ChamferMatcher::Template::show() const
{
int pad = 50;
//Attention size is not correct
Mat templ_color (Size(size.width+(pad*2), size.height+(pad*2)), CV_8UC3);
templ_color.setTo(0);
for (size_t i=0;i<coords.size();++i) {
int x = center.x+coords[i].first+pad;
int y = center.y+coords[i].second+pad;
templ_color.at<Vec3b>(y,x)[1]=255;
//CV_PIXEL(unsigned char, templ_color,x,y)[1] = 255;
if (i%3==0) {
if (orientations[i] < -CV_PI) {
continue;
}
Point p1;
p1.x = x;
p1.y = y;
Point p2;
p2.x = x + pad*(int)(sin(orientations[i])*100)/100;
p2.y = y + pad*(int)(cos(orientations[i])*100)/100;
line(templ_color, p1,p2, CV_RGB(255,0,0));
}
}
circle(templ_color,Point(center.x + pad, center.y + pad),1,CV_RGB(0,255,0));
#ifdef HAVE_OPENCV_HIGHGUI
namedWindow("templ",1);
imshow("templ",templ_color);
cvWaitKey(0);
#else
CV_Error(CV_StsNotImplemented, "OpenCV has been compiled without GUI support");
#endif
templ_color.release();
}
//////////////////////// Matching /////////////////////////////////////
void ChamferMatcher::Matching::addTemplateFromImage(Mat& templ, float scale)
{
Template* cmt = new Template(templ, scale);
templates.clear();
templates.push_back(cmt);
cmt->show();
}
void ChamferMatcher::Matching::addTemplate(Template& template_){
templates.clear();
templates.push_back(&template_);
}
/**
* Alternative version of computeDistanceTransform, will probably be used to compute distance
* transform annotated with edge orientation.
*/
void ChamferMatcher::Matching::computeDistanceTransform(Mat& edges_img, Mat& dist_img, Mat& annotate_img, float truncate_dt, float a = 1.0, float b = 1.5)
{
int d[][2] = { {-1,-1}, { 0,-1}, { 1,-1},
{-1,0}, { 1,0},
{-1,1}, { 0,1}, { 1,1} };
Size s = edges_img.size();
int w = s.width;
int h = s.height;
// set distance to the edge pixels to 0 and put them in the queue
std::queue<std::pair<int,int> > q;
for (int y=0;y<h;++y) {
for (int x=0;x<w;++x) {
// initialize
if (&annotate_img!=NULL) {
annotate_img.at<Vec2i>(y,x)[0]=x;
annotate_img.at<Vec2i>(y,x)[1]=y;
}
uchar edge_val = edges_img.at<uchar>(y,x);
if( (edge_val!=0) ) {
q.push(std::make_pair(x,y));
dist_img.at<float>(y,x)= 0;
}
else {
dist_img.at<float>(y,x)=-1;
}
}
}
// breadth first computation of distance transform
std::pair<int,int> crt;
while (!q.empty()) {
crt = q.front();
q.pop();
int x = crt.first;
int y = crt.second;
float dist_orig = dist_img.at<float>(y,x);
float dist;
for (size_t i=0;i<sizeof(d)/sizeof(d[0]);++i) {
int nx = x + d[i][0];
int ny = y + d[i][1];
if (nx<0 || ny<0 || nx>=w || ny>=h) continue;
if (std::abs(d[i][0]+d[i][1])==1) {
dist = (dist_orig)+a;
}
else {
dist = (dist_orig)+b;
}
float dt = dist_img.at<float>(ny,nx);
if (dt==-1 || dt>dist) {
dist_img.at<float>(ny,nx) = dist;
q.push(std::make_pair(nx,ny));
if (&annotate_img!=NULL) {
annotate_img.at<Vec2i>(ny,nx)[0]=annotate_img.at<Vec2i>(y,x)[0];
annotate_img.at<Vec2i>(ny,nx)[1]=annotate_img.at<Vec2i>(y,x)[1];
}
}
}
}
// truncate dt
if (truncate_dt>0) {
Mat dist_img_thr = dist_img.clone();
threshold(dist_img, dist_img_thr, truncate_dt,0.0 ,THRESH_TRUNC);
dist_img_thr.copyTo(dist_img);
}
}
void ChamferMatcher::Matching::computeEdgeOrientations(Mat& edge_img, Mat& orientation_img)
{
Mat contour_img(edge_img.size(), CV_8UC1);
orientation_img.setTo(3*(-CV_PI));
template_coords_t coords;
template_orientations_t orientations;
while (ChamferMatcher::Matching::findContour(edge_img, coords)) {
ChamferMatcher::Matching::findContourOrientations(coords, orientations);
// set orientation pixel in orientation image
for (size_t i = 0; i<coords.size();++i) {
int x = coords[i].first;
int y = coords[i].second;
// if (orientations[i]>-CV_PI)
// {
//CV_PIXEL(unsigned char, contour_img, x, y)[0] = 255;
contour_img.at<uchar>(y,x)=255;
// }
//CV_PIXEL(float, orientation_img, x, y)[0] = orientations[i];
orientation_img.at<float>(y,x)=orientations[i];
}
coords.clear();
orientations.clear();
}
//imwrite("contours.pgm", contour_img);
}
void ChamferMatcher::Matching::fillNonContourOrientations(Mat& annotated_img, Mat& orientation_img)
{
int cols = annotated_img.cols;
int rows = annotated_img.rows;
assert(orientation_img.cols==cols && orientation_img.rows==rows);
for (int y=0;y<rows;++y) {
for (int x=0;x<cols;++x) {
int xorig = annotated_img.at<Vec2i>(y,x)[0];
int yorig = annotated_img.at<Vec2i>(y,x)[1];
if (x!=xorig || y!=yorig) {
//orientation_img.at<float>(yorig,xorig)=orientation_img.at<float>(y,x);
orientation_img.at<float>(y,x)=orientation_img.at<float>(yorig,xorig);
}
}
}
}
ChamferMatcher::Match* ChamferMatcher::Matching::localChamferDistance(Point offset, Mat& dist_img, Mat& orientation_img,
ChamferMatcher::Template* tpl, float alpha)
{
int x = offset.x;
int y = offset.y;
float beta = 1-alpha;
std::vector<int>& addr = tpl->getTemplateAddresses(dist_img.cols);
float* ptr = dist_img.ptr<float>(y)+x;
float sum_distance = 0;
for (size_t i=0; i<addr.size();++i) {
if(addr[i] < (dist_img.cols*dist_img.rows) - (offset.y*dist_img.cols + offset.x)){
sum_distance += *(ptr+addr[i]);
}
}
float cost = (sum_distance/truncate_)/addr.size();
if (&orientation_img!=NULL) {
float* optr = orientation_img.ptr<float>(y)+x;
float sum_orientation = 0;
int cnt_orientation = 0;
for (size_t i=0;i<addr.size();++i) {
if(addr[i] < (orientation_img.cols*orientation_img.rows) - (offset.y*orientation_img.cols + offset.x)){
if (tpl->orientations[i]>=-CV_PI && (*(optr+addr[i]))>=-CV_PI) {
sum_orientation += orientation_diff(tpl->orientations[i], (*(optr+addr[i])));
cnt_orientation++;
}
}
}
if (cnt_orientation>0) {
cost = (float)(beta*cost+alpha*(sum_orientation/(2*CV_PI))/cnt_orientation);
}
}
if(cost > 0){
ChamferMatcher::Match* istance = new ChamferMatcher::Match();
istance->cost = cost;
istance->offset = offset;
istance->tpl = tpl;
return istance;
}
return NULL;
}
ChamferMatcher::Matches* ChamferMatcher::Matching::matchTemplates(Mat& dist_img, Mat& orientation_img, const ImageRange& range, float _orientation_weight)
{
ChamferMatcher::Matches* pmatches(new Matches());
// try each template
for(size_t i = 0; i < templates.size(); i++) {
ImageIterator* it = range.iterator();
while (it->hasNext()) {
location_scale_t crt = it->next();
Point loc = crt.first;
float scale = crt.second;
Template* tpl = templates[i]->rescale(scale);
if (loc.x-tpl->center.x<0 || loc.x+tpl->size.width/2>=dist_img.cols) continue;
if (loc.y-tpl->center.y<0 || loc.y+tpl->size.height/2>=dist_img.rows) continue;
ChamferMatcher::Match* is = localChamferDistance(loc, dist_img, orientation_img, tpl, _orientation_weight);
if(is)
{
pmatches->push_back(*is);
delete is;
}
}
delete it;
}
return pmatches;
}
/**
* Run matching using an edge image.
* @param edge_img Edge image
* @return a match object
*/
ChamferMatcher::Matches* ChamferMatcher::Matching::matchEdgeImage(Mat& edge_img, const ImageRange& range,
float _orientation_weight, int /*max_matches*/, float /*min_match_distance*/)
{
CV_Assert(edge_img.channels()==1);
Mat dist_img;
Mat annotated_img;
Mat orientation_img;
annotated_img.create(edge_img.size(), CV_32SC2);
dist_img.create(edge_img.size(),CV_32FC1);
dist_img.setTo(0);
// Computing distance transform
computeDistanceTransform(edge_img,dist_img, annotated_img, truncate_);
//orientation_img = NULL;
if (use_orientation_) {
orientation_img.create(edge_img.size(), CV_32FC1);
orientation_img.setTo(0);
Mat edge_clone = edge_img.clone();
computeEdgeOrientations(edge_clone, orientation_img );
edge_clone.release();
fillNonContourOrientations(annotated_img, orientation_img);
}
// Template matching
ChamferMatcher::Matches* pmatches = matchTemplates( dist_img,
orientation_img,
range,
_orientation_weight);
if (use_orientation_) {
orientation_img.release();
}
dist_img.release();
annotated_img.release();
return pmatches;
}
void ChamferMatcher::addMatch(float cost, Point offset, const Template* tpl)
{
bool new_match = true;
for (int i=0; i<count; ++i) {
if (std::abs(matches[i].offset.x-offset.x)+std::abs(matches[i].offset.y-offset.y)<min_match_distance_) {
// too close, not a new match
new_match = false;
// if better cost, replace existing match
if (cost<matches[i].cost) {
matches[i].cost = cost;
matches[i].offset = offset;
matches[i].tpl = tpl;
}
// re-bubble to keep ordered
int k = i;
while (k>0) {
if (matches[k-1].cost>matches[k].cost) {
std::swap(matches[k-1],matches[k]);
}
k--;
}
break;
}
}
if (new_match) {
// if we don't have enough matches yet, add it to the array
if (count<max_matches_) {
matches[count].cost = cost;
matches[count].offset = offset;
matches[count].tpl = tpl;
count++;
}
// otherwise find the right position to insert it
else {
// if higher cost than the worst current match, just ignore it
if (matches[count-1].cost<cost) {
return;
}
int j = 0;
// skip all matches better than current one
while (matches[j].cost<cost) j++;
// shift matches one position
int k = count-2;
while (k>=j) {
matches[k+1] = matches[k];
k--;
}
matches[j].cost = cost;
matches[j].offset = offset;
matches[j].tpl = tpl;
}
}
}
void ChamferMatcher::showMatch(Mat& img, int index)
{
if (index>=count) {
std::cout << "Index too big.\n" << std::endl;
}
assert(img.channels()==3);
Match match = matches[index];
const template_coords_t& templ_coords = match.tpl->coords;
int x, y;
for (size_t i=0;i<templ_coords.size();++i) {
x = match.offset.x + templ_coords[i].first;
y = match.offset.y + templ_coords[i].second;
if ( x > img.cols-1 || x < 0 || y > img.rows-1 || y < 0) continue;
img.at<Vec3b>(y,x)[0]=0;
img.at<Vec3b>(y,x)[2]=0;
img.at<Vec3b>(y,x)[1]=255;
}
}
void ChamferMatcher::showMatch(Mat& img, Match match)
{
assert(img.channels()==3);
const template_coords_t& templ_coords = match.tpl->coords;
for (size_t i=0;i<templ_coords.size();++i) {
int x = match.offset.x + templ_coords[i].first;
int y = match.offset.y + templ_coords[i].second;
if ( x > img.cols-1 || x < 0 || y > img.rows-1 || y < 0) continue;
img.at<Vec3b>(y,x)[0]=0;
img.at<Vec3b>(y,x)[2]=0;
img.at<Vec3b>(y,x)[1]=255;
}
match.tpl->show();
}
const ChamferMatcher::Matches& ChamferMatcher::matching(Template& tpl, Mat& image_){
chamfer_->addTemplate(tpl);
matches.clear();
matches.resize(max_matches_);
count = 0;
Matches* matches_ = chamfer_->matchEdgeImage( image_,
ChamferMatcher::
SlidingWindowImageRange(image_.cols,
image_.rows,
pad_x,
pad_y,
scales,
minScale,
maxScale),
orientation_weight,
max_matches_,
min_match_distance_);
for(int i = 0; i < (int)matches_->size(); i++){
addMatch(matches_->at(i).cost, matches_->at(i).offset, matches_->at(i).tpl);
}
matches_->clear();
delete matches_;
matches_ = NULL;
matches.resize(count);
return matches;
}
int chamerMatching( Mat& img, Mat& templ,
std::vector<std::vector<Point> >& results, std::vector<float>& costs,
double templScale, int maxMatches, double minMatchDistance, int padX,
int padY, int scales, double minScale, double maxScale,
double orientationWeight, double truncate )
{
CV_Assert(img.type() == CV_8UC1 && templ.type() == CV_8UC1);
ChamferMatcher matcher_(maxMatches, (float)minMatchDistance, padX, padY, scales,
(float)minScale, (float)maxScale,
(float)orientationWeight, (float)truncate);
ChamferMatcher::Template template_(templ, (float)templScale);
ChamferMatcher::Matches match_instances = matcher_.matching(template_, img);
size_t i, nmatches = match_instances.size();
results.resize(nmatches);
costs.resize(nmatches);
int bestIdx = -1;
double minCost = DBL_MAX;
for( i = 0; i < nmatches; i++ )
{
const ChamferMatcher::Match& match = match_instances[i];
double cval = match.cost;
if( cval < minCost)
{
minCost = cval;
bestIdx = (int)i;
}
costs[i] = (float)cval;
const template_coords_t& templ_coords = match.tpl->coords;
std::vector<Point>& templPoints = results[i];
size_t j, npoints = templ_coords.size();
templPoints.resize(npoints);
for (j = 0; j < npoints; j++ )
{
int x = match.offset.x + templ_coords[j].first;
int y = match.offset.y + templ_coords[j].second;
templPoints[j] = Point(x,y);
}
}
return bestIdx;
}
}