papillon/src/papillon.cpp
2016-05-30 14:30:13 +02:00

303 lines
8.6 KiB
C++

#include "ros/ros.h"
#include <image_transport/image_transport.h>
#include <cv_bridge/cv_bridge.h>
#include <sensor_msgs/image_encodings.h>
#include <opencv/cv.h>
#include <sstream>
using namespace cv;
using namespace std;
class Traite_image {
public:
const static int SENSITIVITY_VALUE = 30;
const static int BLUR_SIZE = 10;
const int HORIZONTAL_BORDER_CROP = 20; // In pixels. Crops the border to reduce the black borders from stabilisation being too noticeable.
Mat prev;
Mat last_T;
bool first = true;
int resize_f = 1;
int theObject[2] = {0,0};
Rect objectBoundingRectangle = Rect(0,0,0,0);
ros::NodeHandle n;
image_transport::ImageTransport it;
image_transport::Publisher pub;
image_transport::Subscriber sub;
Traite_image() : n("~"),it(n) {
pub = it.advertise("/image_out", 1);
sub = it.subscribe("/usb_cam/image_raw", 1, [this](const sensor_msgs::ImageConstPtr& img) -> void { this->on_image(img);},ros::VoidPtr(),image_transport::TransportHints("compressed"));
}
// This processes an image and publishes the result.
void on_image(const sensor_msgs::ImageConstPtr& msg) {
cv_bridge::CvImageConstPtr bridge_input;
try {
bridge_input = cv_bridge::toCvShare(msg,sensor_msgs::image_encodings::RGB8);
}
catch (Exception& e) {
std::ostringstream errstr;
errstr << "cv_bridge exception caught: " << e.what();
return;
}
//Mat& input = const_cast<Mat&>(bridge_input->image);
const Mat& input = bridge_input->image;
Mat next;
resize(input, next, Size(input.size().width/resize_f, input.size().height/resize_f));
Mat output;// = input.clone(); // (input.rows, input.cols, CV_32FC2);
//ROS_INFO("got input");
if (first) {
prev = next.clone();
first = false;
ROS_INFO("first done");
}
Mat next_stab;
stabiliseImg(prev, next, next_stab);
Rect myROI(next_stab.size().width/8, next_stab.size().height/8, next_stab.size().width*3/4, next_stab.size().height*3/4);
Mat next_stab_cropped = next_stab(myROI);
Mat prev_cropped = prev(myROI);
searchForMovement(prev_cropped, next_stab_cropped, output);
pub.publish(cv_bridge::CvImage(msg->header, "rgb8", output).toImageMsg());
// bridge_input is handled by a smart-pointer. No explicit delete needed.
//ROS_INFO("pub");
prev = next.clone();
}
//int to string helper function
string intToString(int number){
//this function has a number input and string output
std::stringstream ss;
ss << number;
return ss.str();
}
void stabiliseImg(Mat prev, Mat cur, Mat &output){
Mat cur_grey, prev_grey;
cvtColor(cur, cur_grey, COLOR_BGR2GRAY);
cvtColor(prev, prev_grey, COLOR_BGR2GRAY);
// vector from prev to cur
vector <Point2f> prev_corner, cur_corner;
vector <Point2f> prev_corner2, cur_corner2;
vector <uchar> status;
vector <float> err;
goodFeaturesToTrack(prev_grey, prev_corner, 200, 0.01, 30);
calcOpticalFlowPyrLK(prev_grey, cur_grey, prev_corner, cur_corner, status, err);
// weed out bad matches
for(size_t i=0; i < status.size(); i++) {
if(status[i]) {
prev_corner2.push_back(prev_corner[i]);
cur_corner2.push_back(cur_corner[i]);
}
}
Mat T = estimateRigidTransform(prev_corner2, cur_corner2, true); // false = rigid transform, no scaling/shearing
if(T.data == NULL) {
last_T.copyTo(T);
}
T.copyTo(last_T);
Mat cur2;
warpAffine(cur, cur2, T, cur.size(),INTER_NEAREST|WARP_INVERSE_MAP);
cur2.copyTo(output);
}
void searchForMovement(Mat prev, Mat cur, Mat &output){
Mat cur_grey, prev_grey;
cur.copyTo(output);
cvtColor(prev, prev_grey, COLOR_BGR2GRAY);
cvtColor(cur, cur_grey, COLOR_BGR2GRAY);
// Subtract the 2 last frames and threshold them
Mat thres;
absdiff(prev_grey,cur_grey,thres);
threshold(thres, thres, SENSITIVITY_VALUE, 255, THRESH_BINARY);
// Blur to eliminate noise
blur(thres, thres, Size(BLUR_SIZE, BLUR_SIZE));
threshold(thres, thres, SENSITIVITY_VALUE, 255, THRESH_BINARY);
//notice how we use the '&' operator for objectDetected and output. This is because we wish
//to take the values passed into the function and manipulate them, rather than just working with a copy.
//eg. we draw to the output to be displayed in the main() function.
bool objectDetected = false;
Mat temp;
thres.copyTo(temp);
//these two vectors needed for output of findContours
vector< vector<Point> > contours;
vector<Vec4i> hierarchy;
//find contours of filtered image using openCV findContours function
//findContours(temp,contours,hierarchy,CV_RETR_CCOMP,CV_CHAIN_APPROX_SIMPLE );// retrieves all contours
findContours(temp,contours,hierarchy,CV_RETR_EXTERNAL,CV_CHAIN_APPROX_SIMPLE );// retrieves external contours
//if contours vector is not empty, we have found some objects
if(contours.size()>0)objectDetected=true;
else objectDetected = false;
if(objectDetected){
//the largest contour is found at the end of the contours vector
//we will simply assume that the biggest contour is the object we are looking for.
vector< vector<Point> > largestContourVec;
largestContourVec.push_back(contours.at(contours.size()-1));
//make a bounding rectangle around the largest contour then find its centroid
//this will be the object's final estimated position.
objectBoundingRectangle = boundingRect(largestContourVec.at(0));
}
//make some temp x and y variables so we dont have to type out so much
int x = objectBoundingRectangle.x;
int y = objectBoundingRectangle.y;
int width = objectBoundingRectangle.width;
int height = objectBoundingRectangle.height;
//draw a rectangle around the object
rectangle(output, Point(x,y), Point(x+width, y+height), Scalar(0, 255, 0), 2);
//write the position of the object to the screen
putText(output,"Tracking object at (" + intToString(x)+","+intToString(y)+")",Point(x,y),1,1,Scalar(255,0,0),2);
}
inline bool isFlowCorrect(Point2f u)
{
return !cvIsNaN(u.x) && !cvIsNaN(u.y) && fabs(u.x) < 1e9 && fabs(u.y) < 1e9;
}
Vec3b computeColor(float fx, float fy)
{
static bool first = true;
// relative lengths of color transitions:
// these are chosen based on perceptual similarity
// (e.g. one can distinguish more shades between red and yellow
// than between yellow and green)
const int RY = 15;
const int YG = 6;
const int GC = 4;
const int CB = 11;
const int BM = 13;
const int MR = 6;
const int NCOLS = RY + YG + GC + CB + BM + MR;
static Vec3i colorWheel[NCOLS];
if (first)
{
int k = 0;
for (int i = 0; i < RY; ++i, ++k)
colorWheel[k] = Vec3i(255, 255 * i / RY, 0);
for (int i = 0; i < YG; ++i, ++k)
colorWheel[k] = Vec3i(255 - 255 * i / YG, 255, 0);
for (int i = 0; i < GC; ++i, ++k)
colorWheel[k] = Vec3i(0, 255, 255 * i / GC);
for (int i = 0; i < CB; ++i, ++k)
colorWheel[k] = Vec3i(0, 255 - 255 * i / CB, 255);
for (int i = 0; i < BM; ++i, ++k)
colorWheel[k] = Vec3i(255 * i / BM, 0, 255);
for (int i = 0; i < MR; ++i, ++k)
colorWheel[k] = Vec3i(255, 0, 255 - 255 * i / MR);
first = false;
}
const float rad = sqrt(fx * fx + fy * fy);
const float a = atan2(-fy, -fx) / (float)CV_PI;
const float fk = (a + 1.0f) / 2.0f * (NCOLS - 1);
const int k0 = static_cast<int>(fk);
const int k1 = (k0 + 1) % NCOLS;
const float f = fk - k0;
Vec3b pix;
for (int b = 0; b < 3; b++)
{
const float col0 = colorWheel[k0][b] / 255.f;
const float col1 = colorWheel[k1][b] / 255.f;
float col = (1 - f) * col0 + f * col1;
if (rad <= 1)
col = 1 - rad * (1 - col); // increase saturation with radius
else
col *= .75; // out of range
pix[2 - b] = static_cast<uchar>(255.f * col);
}
return pix;
}
void drawOpticalFlow(const Mat_<Point2f>& flow, Mat& dst, float maxmotion = -1)
{
dst.create(flow.size(), CV_8UC3);
dst.setTo(Scalar::all(0));
// determine motion range:
float maxrad = maxmotion;
if (maxmotion <= 0)
{
maxrad = 1;
for (int y = 0; y < flow.rows; ++y)
{
for (int x = 0; x < flow.cols; ++x)
{
Point2f u = flow(y, x);
if (!isFlowCorrect(u))
continue;
maxrad = max(maxrad, sqrt(u.x * u.x + u.y * u.y));
}
}
}
for (int y = 0; y < flow.rows; ++y)
{
for (int x = 0; x < flow.cols; ++x)
{
Point2f u = flow(y, x);
if (isFlowCorrect(u))
dst.at<Vec3b>(y, x) = computeColor(u.x / maxrad, u.y / maxrad);
}
}
}
};
int main(int argc, char **argv)
{
ros::init(argc, argv, "test_opencv");
Traite_image dataset=Traite_image();
ros::spin();
return 0;
}