OpenCV Image processing

[donald83180]

I have to take a bmp file with multiple rectangles and determine corner points and angle of rotation. I've started with a canny and a hough transform, but can't seem to determine the corners to continue. Below is what I have written so far. Any guidance in the right direction would be greatly appreciated.

#include<opencv\cv.h>
#include<opencv\highgui.h>
#include<iostream>
using namespace cv;
using namespace std;
using namespace cv;
/// Global variables
Mat src, src_gray;
Mat dst, cdst, ldst, detected_edges;
vector<Vec4i> lines;
int edgeThresh = 1;
int const lowThreshold = 5;
int const maxThreshold = 200;
int ratio = 3;
int kernel_size = 3;
char* window_name1 = "Edge Map";
char* window_name2 = "Line Map";

int main()
{
//Load boxes.bmp into a matrix
src = imread( "boxes.bmp",1 );
//convert boxes.bmp into grayscale
cvtColor( src, src_gray, CV_BGR2GRAY );
/// Reduce noise with a kernel 3x3
blur( src_gray, detected_edges, Size(3,3) );
/// Canny detector
Canny( detected_edges, detected_edges, lowThreshold, maxThreshold, kernel_size );
/// Using Canny's output as a mask, we display our result
src.copyTo( dst, detected_edges);
cvtColor( dst, cdst, CV_BGR2GRAY );
HoughLinesP( cdst, lines, 25, CV_PI/180, 1, 0, 0);
for( size_t i = 0; i < lines.size(); i++ )
{
int x1 = lines[i][0];
int x2 = lines[i][2];
int y1 = lines[i][1];
int y2 = lines[i][3];
line( cdst, Point(x1, y1),
Point(x2, y2), Scalar(255,255,255), 1, 8 );
}
imshow( "Source", src );

imshow( "Detected Lines", cdst );

waitKey();
};