【opencv练习39 - Harris角点】

/*******************************************************************
测试程序  Harris角点
时间：2016年9月6日
********************************************************************/

Mat src, src_gray;
int thresh = 200;
int max_thresh = 255;

const char* source_window = "Source image";
const char* corners_window = "Corners detected";

/// Function header
void cornerHarris_demo( int, void* );

int main(void)
{
//加载&灰度化
src = imread( "Image.jpg", 1 );
cvtColor( src, src_gray, COLOR_BGR2GRAY );
namedWindow( source_window, WINDOW_AUTOSIZE );
createTrackbar( "Threshold: ", source_window, &thresh, max_thresh, cornerHarris_demo );
imshow( source_window, src );

cornerHarris_demo( 0, 0 );

waitKey(0);
return(0);
}

//* @brief 【执行角点检测，对可能的角点绘制圈】
//* Executes the corner detection and draw a circle around the possible corners

void cornerHarris_demo( int, void* )
{

Mat dst, dst_norm, dst_norm_scaled;
dst = Mat::zeros( src.size(), CV_32FC1 );

//【检测子参数】
int blockSize = 2;                    //块大小
int apertureSize = 3;                 //孔径
double k = 0.04;

//【检测角点】
//【计算每一像素的Harris cornerness 测度】
cornerHarris( src_gray, dst, blockSize, apertureSize, k, BORDER_DEFAULT );

//【归一化】
normalize( dst, dst_norm, 0, 255, NORM_MINMAX, CV_32FC1, Mat() );
convertScaleAbs( dst_norm, dst_norm_scaled );

//【绘制角点圈】
for( int j = 0; j < dst_norm.rows ; j++ )
{ for( int i = 0; i < dst_norm.cols; i++ )
{
if( (int) dst_norm.at<float>(j,i) > thresh )
{
circle( dst_norm_scaled, Point( i, j ), 5,  Scalar(255), 2, 8, 0 );
}
}
}

namedWindow( corners_window, WINDOW_AUTOSIZE );
imshow( corners_window, dst_norm_scaled );

}