diff options
Diffstat (limited to 'ftnoir_tracker_pt/point_extractor.cpp')
| -rw-r--r-- | ftnoir_tracker_pt/point_extractor.cpp | 163 |
1 files changed, 163 insertions, 0 deletions
diff --git a/ftnoir_tracker_pt/point_extractor.cpp b/ftnoir_tracker_pt/point_extractor.cpp new file mode 100644 index 00000000..d9ff0a5b --- /dev/null +++ b/ftnoir_tracker_pt/point_extractor.cpp @@ -0,0 +1,163 @@ +/* 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);
+}
+// ----------------------------------------------------------------------------
+const vector<Vec2f>& PointExtractor::extract_points(Mat frame, float dt, bool draw_output)
+{
+ const int W = frame.cols;
+ const int H = frame.rows;
+
+ if (frame_last.cols != W || frame_last.rows != H)
+ {
+ frame_last = cv::Mat();
+ }
+
+ // clear old points
+ points.clear();
+
+ // convert to grayscale
+ Mat frame_gray;
+ cvtColor(frame, frame_gray, CV_RGB2GRAY);
+
+ int secondary = threshold_secondary_val;
+
+ // 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, threshold_val, 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 = threshold_val;
+ //float hyst = float(threshold_secondary_val)/512.;
+ //threshold(frame_gray, frame_bin, (t + ((255.-t)*hyst)), 255, THRESH_BINARY);
+ float hyst = float(threshold_secondary_val)/256.;
+ 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);
+
+ if(draw_output) 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);
+ }
+ }
+ 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;
+
+ int blob_index = 1;
+ for (int y=0; y<H; y++)
+ {
+ if (blob_index >= 255) break;
+ for (int x=0; x<W; x++)
+ {
+ if (blob_index >= 255) break;
+
+ // find connected components with floodfill
+ if (frame_bin.at<unsigned char>(y,x) != 255) continue;
+ Rect rect;
+
+ floodFill(frame_bin, Point(x,y), Scalar(blob_index), &rect, Scalar(0), Scalar(0), FLOODFILL_FIXED_RANGE);
+ blob_index++;
+
+ // calculate the size of the connected component
+ unsigned int region_size = 0;
+ for (int i=rect.y; i < (rect.y+rect.height); i++)
+ {
+ for (int j=rect.x; j < (rect.x+rect.width); j++)
+ {
+ if (frame_bin.at<unsigned char>(i,j) != blob_index-1) continue;
+ region_size++;
+ }
+ }
+
+ if (region_size < region_size_min || region_size > region_size_max) continue;
+
+ // calculate the center of mass:
+ // mx = (sum_ij j*f(frame_grey_ij)) / (sum_ij f(frame_grey_ij))
+ // my = ...
+ // f maps from [threshold,256] -> [0, 1], lower values are mapped to 0
+ float m = 0;
+ float mx = 0;
+ float my = 0;
+ for (int i=rect.y; i < (rect.y+rect.height); i++)
+ {
+ for (int j=rect.x; j < (rect.x+rect.width); j++)
+ {
+ if (frame_bin.at<unsigned char>(i,j) != blob_index-1) continue;
+ float val;
+
+ if(secondary==0){
+ val = frame_gray.at<unsigned char>(i,j);
+ val = float(val - threshold_val)/(256 - threshold_val);
+ val = val*val; // makes it more stable (less emphasis on low values, more on the peak)
+ }else{
+ //hysteresis point detection gets stability from ignoring pixel noise so we decidedly leave the actual pixel values out of the picture
+ val = frame_last.at<unsigned char>(i,j) / 256.;
+ }
+
+ m += val;
+ mx += j * val;
+ my += i * val;
+ }
+ }
+
+ // convert to centered camera coordinate system with y axis upwards
+ Vec2f c;
+ c[0] = (mx/m - W/2)/W;
+ c[1] = -(my/m - H/2)/W;
+ //qDebug()<<blob_index<<" => "<<c[0]<<" "<<c[1];
+ points.push_back(c);
+ }
+ }
+
+ // draw output image
+ if (draw_output) {
+ vector<Mat> channels;
+ if(secondary==0){
+ 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);
+ }else{
+ frame_bin_copy.setTo(120, frame_bin_copy);
+ frame_bin_low.setTo(90, frame_bin_low);
+ channels.push_back(frame_gray + frame_bin_copy);
+ channels.push_back(frame_gray + frame_last_and_low);
+ channels.push_back(frame_gray + frame_bin_low);
+ //channels.push_back(frame_gray + frame_bin);
+ }
+ merge(channels, frame);
+ }
+
+ return points;
+}
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