opencv/modules/contrib/src/quadsubpix.cpp

366 lines
12 KiB
C++

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#include "precomp.hpp"
#include <limits>
#include <utility>
#include <algorithm>
#include <math.h>
//#define _SUBPIX_VERBOSE
#undef max
namespace cv {
void drawCircles(Mat& img, const vector<Point2f>& corners, const vector<float>& radius)
{
for(size_t i = 0; i < corners.size(); i++)
{
circle(img, corners[i], cvRound(radius[i]), CV_RGB(255, 0, 0));
}
}
int histQuantile(const MatND& hist, float quantile)
{
if(hist.dims > 1) return -1; // works for 1D histograms only
float cur_sum = 0;
float total_sum = (float)sum(hist).val[0];
float quantile_sum = total_sum*quantile;
for(int j = 0; j < hist.size[0]; j++)
{
cur_sum += (float)hist.at<double>(j);
if(cur_sum > quantile_sum)
{
return j;
}
}
return hist.size[0] - 1;
}
bool is_smaller(const std::pair<int, float>& p1, const std::pair<int, float>& p2)
{
return p1.second < p2.second;
}
void orderContours(const vector<vector<Point> >& contours, Point2f point, vector<std::pair<int, float> >& order)
{
order.clear();
int i, j, n = (int)contours.size();
for(i = 0; i < n; i++)
{
double min_dist = std::numeric_limits<double>::max();
for(j = 0; j < n; j++)
{
double dist = norm(Point2f((float)contours[i][j].x, (float)contours[i][j].y) - point);
min_dist = MIN(min_dist, dist);
}
order.push_back(std::pair<int, float>(i, (float)min_dist));
}
std::sort(order.begin(), order.end(), is_smaller);
}
// fit second order curve to a set of 2D points
void fitCurve2Order(const vector<Point2f>& /*points*/, vector<float>& /*curve*/)
{
// TBD
}
void findCurvesCross(const vector<float>& /*curve1*/, const vector<float>& /*curve2*/, Point2f& /*cross_point*/)
{
}
void findLinesCrossPoint(Point2f origin1, Point2f dir1, Point2f origin2, Point2f dir2, Point2f& cross_point)
{
float det = dir2.x*dir1.y - dir2.y*dir1.x;
Point2f offset = origin2 - origin1;
float alpha = (dir2.x*offset.y - dir2.y*offset.x)/det;
cross_point = origin1 + dir1*alpha;
}
void findCorner(const vector<Point>& contour, Point2f point, Point2f& corner)
{
// find the nearest point
double min_dist = std::numeric_limits<double>::max();
int min_idx = -1;
Rect brect = boundingRect(Mat(contour));
// find corner idx
for(size_t i = 0; i < contour.size(); i++)
{
double dist = norm(Point2f((float)contour[i].x, (float)contour[i].y) - point);
if(dist < min_dist)
{
min_dist = dist;
min_idx = (int)i;
}
}
assert(min_idx >= 0);
// temporary solution, have to make something more precise
corner = contour[min_idx];
return;
}
void findCorner(const vector<Point2f>& contour, Point2f point, Point2f& corner)
{
// find the nearest point
double min_dist = std::numeric_limits<double>::max();
int min_idx = -1;
Rect brect = boundingRect(Mat(contour));
// find corner idx
for(size_t i = 0; i < contour.size(); i++)
{
double dist = norm(contour[i] - point);
if(dist < min_dist)
{
min_dist = dist;
min_idx = (int)i;
}
}
assert(min_idx >= 0);
// temporary solution, have to make something more precise
corner = contour[min_idx];
return;
}
int segment_hist_max(const MatND& hist, int& low_thresh, int& high_thresh)
{
Mat bw;
//const double max_bell_width = 20; // we expect two bells with width bounded above
//const double min_bell_width = 5; // and below
double total_sum = sum(hist).val[0];
//double thresh = total_sum/(2*max_bell_width)*0.25f; // quarter of a bar inside a bell
// threshold(hist, bw, thresh, 255.0, CV_THRESH_BINARY);
double quantile_sum = 0.0;
//double min_quantile = 0.2;
double low_sum = 0;
double max_segment_length = 0;
int max_start_x = -1;
int max_end_x = -1;
int start_x = 0;
const double out_of_bells_fraction = 0.1;
for(int x = 0; x < hist.size[0]; x++)
{
quantile_sum += hist.at<double>(x);
if(quantile_sum < 0.2*total_sum) continue;
if(quantile_sum - low_sum > out_of_bells_fraction*total_sum)
{
if(max_segment_length < x - start_x)
{
max_segment_length = x - start_x;
max_start_x = start_x;
max_end_x = x;
}
low_sum = quantile_sum;
start_x = x;
}
}
if(start_x == -1)
{
return 0;
}
else
{
low_thresh = cvRound(max_start_x + 0.25*(max_end_x - max_start_x));
high_thresh = cvRound(max_start_x + 0.75*(max_end_x - max_start_x));
return 1;
}
}
bool find4QuadCornerSubpix(const Mat& img, std::vector<Point2f>& corners, Size region_size)
{
const int nbins = 256;
float ranges[] = {0, 256};
const float* _ranges = ranges;
MatND hist;
#if defined(_SUBPIX_VERBOSE)
vector<float> radius;
radius.assign(corners.size(), 0.0f);
#endif //_SUBPIX_VERBOSE
Mat black_comp, white_comp;
for(size_t i = 0; i < corners.size(); i++)
{
int channels = 0;
Rect roi(cvRound(corners[i].x - region_size.width), cvRound(corners[i].y - region_size.height),
region_size.width*2 + 1, region_size.height*2 + 1);
Mat img_roi = img(roi);
calcHist(&img_roi, 1, &channels, Mat(), hist, 1, &nbins, &_ranges);
#if 0
int black_thresh = histQuantile(hist, 0.45f);
int white_thresh = histQuantile(hist, 0.55f);
#else
int black_thresh, white_thresh;
segment_hist_max(hist, black_thresh, white_thresh);
#endif
threshold(img, black_comp, black_thresh, 255.0, CV_THRESH_BINARY_INV);
threshold(img, white_comp, white_thresh, 255.0, CV_THRESH_BINARY);
const int erode_count = 1;
erode(black_comp, black_comp, Mat(), Point(-1, -1), erode_count);
erode(white_comp, white_comp, Mat(), Point(-1, -1), erode_count);
#if defined(_SUBPIX_VERBOSE)
namedWindow("roi", 1);
imshow("roi", img_roi);
imwrite("test.jpg", img);
namedWindow("black", 1);
imshow("black", black_comp);
namedWindow("white", 1);
imshow("white", white_comp);
cvWaitKey(0);
imwrite("black.jpg", black_comp);
imwrite("white.jpg", white_comp);
#endif
vector<vector<Point> > white_contours, black_contours;
vector<Vec4i> white_hierarchy, black_hierarchy;
findContours(black_comp, black_contours, black_hierarchy, CV_RETR_LIST, CV_CHAIN_APPROX_SIMPLE);
findContours(white_comp, white_contours, white_hierarchy, CV_RETR_LIST, CV_CHAIN_APPROX_SIMPLE);
if(black_contours.size() < 5 || white_contours.size() < 5) continue;
// find two white and black blobs that are close to the input point
vector<std::pair<int, float> > white_order, black_order;
orderContours(black_contours, corners[i], black_order);
orderContours(white_contours, corners[i], white_order);
const float max_dist = 10.0f;
if(black_order[0].second > max_dist || black_order[1].second > max_dist ||
white_order[0].second > max_dist || white_order[1].second > max_dist)
{
continue; // there will be no improvement in this corner position
}
const vector<Point>* quads[4] = {&black_contours[black_order[0].first], &black_contours[black_order[1].first],
&white_contours[white_order[0].first], &white_contours[white_order[1].first]};
vector<Point2f> quads_approx[4];
Point2f quad_corners[4];
for(int k = 0; k < 4; k++)
{
#if 1
vector<Point2f> temp;
for(size_t j = 0; j < quads[k]->size(); j++) temp.push_back((*quads[k])[j]);
approxPolyDP(Mat(temp), quads_approx[k], 0.5, true);
findCorner(quads_approx[k], corners[i], quad_corners[k]);
#else
findCorner(*quads[k], corners[i], quad_corners[k]);
#endif
quad_corners[k] += Point2f(0.5f, 0.5f);
}
// cross two lines
Point2f origin1 = quad_corners[0];
Point2f dir1 = quad_corners[1] - quad_corners[0];
Point2f origin2 = quad_corners[2];
Point2f dir2 = quad_corners[3] - quad_corners[2];
double angle = acos(dir1.dot(dir2)/(norm(dir1)*norm(dir2)));
if(cvIsNaN(angle) || cvIsInf(angle) || angle < 0.5 || angle > CV_PI - 0.5) continue;
findLinesCrossPoint(origin1, dir1, origin2, dir2, corners[i]);
#if defined(_SUBPIX_VERBOSE)
radius[i] = norm(corners[i] - ground_truth_corners[ground_truth_idx])*6;
#if 1
Mat test(img.size(), CV_32FC3);
cvtColor(img, test, CV_GRAY2RGB);
// line(test, quad_corners[0] - corners[i] + Point2f(30, 30), quad_corners[1] - corners[i] + Point2f(30, 30), cvScalar(0, 255, 0));
// line(test, quad_corners[2] - corners[i] + Point2f(30, 30), quad_corners[3] - corners[i] + Point2f(30, 30), cvScalar(0, 255, 0));
vector<vector<Point> > contrs;
contrs.resize(1);
for(int k = 0; k < 4; k++)
{
//contrs[0] = quads_approx[k];
contrs[0].clear();
for(size_t j = 0; j < quads_approx[k].size(); j++) contrs[0].push_back(quads_approx[k][j]);
drawContours(test, contrs, 0, CV_RGB(0, 0, 255), 1, 1, vector<Vec4i>(), 2);
circle(test, quad_corners[k], 0.5, CV_RGB(255, 0, 0));
}
Mat test1 = test(Rect(corners[i].x - 30, corners[i].y - 30, 60, 60));
namedWindow("1", 1);
imshow("1", test1);
imwrite("test.jpg", test);
waitKey(0);
#endif
#endif //_SUBPIX_VERBOSE
}
#if defined(_SUBPIX_VERBOSE)
Mat test(img.size(), CV_32FC3);
cvtColor(img, test, CV_GRAY2RGB);
drawCircles(test, corners, radius);
namedWindow("corners", 1);
imshow("corners", test);
waitKey();
#endif //_SUBPIX_VERBOSE
return true;
}
}; // namespace std