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/* Copyright (c) 2012 Patrick Ruoff
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*/
#include "point_extractor.h"
#include <QDebug>
using namespace cv;
using namespace std;
PointExtractor::PointExtractor(){
//if (!AllocConsole()){}
//else SetConsoleTitle("debug");
//freopen("CON", "w", stdout);
//freopen("CON", "w", stderr);
}
// ----------------------------------------------------------------------------
std::vector<Vec2f> PointExtractor::extract_points(Mat& frame)
{
const int W = frame.cols;
const int H = frame.rows;
if (frame_last.cols != W || frame_last.rows != H)
{
frame_last = cv::Mat();
}
// convert to grayscale
Mat frame_gray;
cvtColor(frame, frame_gray, cv::COLOR_RGB2GRAY);
int secondary = s.threshold_secondary;
int primary = s.threshold;
// mask for everything that passes the threshold (or: the upper threshold of the hysteresis)
Mat frame_bin;
// only used if draw_output
Mat frame_bin_copy;
// mask for everything that passes
Mat frame_bin_low;
// mask for lower-threshold && combined result of last, needs to remain in scope until drawing, but is only used if secondary != 0
Mat frame_last_and_low;
if(secondary==0){
threshold(frame_gray, frame_bin, primary, 255, THRESH_BINARY);
}else{
// we recombine a number of buffers, this might be slower than a single loop of per-pixel logic
// but it might as well be faster if openCV makes good use of SIMD
float t = primary;
//float hyst = float(threshold_secondary_val)/512.;
//threshold(frame_gray, frame_bin, (t + ((255.-t)*hyst)), 255, THRESH_BINARY);
float hyst = float(primary)/(256.*8.);
threshold(frame_gray, frame_bin, t, 255, THRESH_BINARY);
threshold(frame_gray, frame_bin_low,std::max(float(1), t - (t*hyst)), 255, THRESH_BINARY);
frame_bin.copyTo(frame_bin_copy);
if(frame_last.empty()){
frame_bin.copyTo(frame_last);
}else{
// keep pixels from last if they are above lower threshold
bitwise_and(frame_last, frame_bin_low, frame_last_and_low);
// union of pixels >= higher threshold and pixels >= lower threshold
bitwise_or(frame_bin, frame_last_and_low, frame_last);
frame_last.copyTo(frame_bin);
}
}
int min_size = s.min_point_size;
int max_size = s.max_point_size;
unsigned int region_size_min = 3.14*min_size*min_size/4.0;
unsigned int region_size_max = 3.14*max_size*max_size/4.0;
std::vector<std::vector<cv::Point>> contours;
cv::findContours(frame_bin, contours, CV_RETR_LIST, CV_CHAIN_APPROX_SIMPLE);
// clear old points
points.clear();
for (auto& c : contours)
{
auto m = cv::moments(cv::Mat(c));
const double area = m.m00;
if (area == 0.)
continue;
cv::Vec2f pos(m.m10 / m.m00, m.m01 / m.m00);
if (area < region_size_min || area > region_size_max)
continue;
pos[0] = (pos[0] - W/2)/W;
pos[1] = -(pos[1] - H/2)/W;
points.push_back(pos);
}
// draw output image
vector<Mat> channels;
frame_bin.setTo(170, frame_bin);
channels.push_back(frame_gray + frame_bin);
channels.push_back(frame_gray - frame_bin);
channels.push_back(frame_gray - frame_bin);
merge(channels, frame);
return points;
}
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