# Revision history [back]

Hi Berek,

In iris recognition, you locate the pupil and then the Iris using canny edge and Hough transform.

There ar

Hi Berek,

In iris recognition, you locate the pupil and then the Iris using canny edge and Hough transform.

There ar

First we calculte the pupil centriods using concept of contours:

static Mat getpupil(Mat& frame,Point& centroids){
Mat pupilImg = Mat(frame.size(), CV_8UC1);
Mat grayImg = Mat(frame.size(), CV_8UC1);
Mat tframe = frame;
Mat resImg;
inRange(frame, Scalar(28,28,28), Scalar(75,75,75), pupilImg);
vector<vector<Point>> contours;
vector<Vec4i> hierarchy;
RNG rng(12345);
findContours(pupilImg, contours, hierarchy, CV_RETR_TREE, CV_CHAIN_APPROX_SIMPLE);
pupilImg.release();
pupilImg = frame.clone();
for (int i = 0; i < contours.size(); i++){
Moments mom = moments(contours[i]);
double area = mom.m00;
if (area > 50){
double pupilArea = area;
double x = mom.m10/area;
double y = mom.m01/area;
vector<vector<Point>> pupils = contours;
centroids = Point((int)x, (int)y);
Scalar color = Scalar(0, 0, 0);
drawContours(pupilImg, pupils,hierarchy[i][3], CV_RGB(0,0,0),CV_FILLED,8,hierarchy);
break;
}
}
return pupilImg;


}

Then we use Hough transform to find the Iris

static Mat getIris(Mat& frame,Point& centroid,int& rad){
Mat copyImg = frame.clone();
Mat Cf;
frame.copyTo(Cf);
Mat resImg = frame.clone();
Mat grayImg = Mat(frame.size(), CV_8UC1);
Mat Storage = Mat(frame.cols, 1, CV_32FC3);
int x1, y1;
Canny(frame, grayImg, 5, 70, 3);
GaussianBlur(grayImg, grayImg, Size(7, 7), 0);
vector<Vec3f> circles = getCircles(grayImg);

for (int i = 0; i < circles.size(); i++){
x1 = cvRound(circles[i][0]);
y1 = cvRound(circles[i][1]);
int x = centroid.x - rad;
int y = centroid.y - rad;
int w = rad * 2;
int h = w;
34    resImg = resImg(Rect(x,y,w,h));
Mat cropImg = Mat(Size(w,h), CV_8UC1);
resImg.copyTo(cropImg);
resImg = resImg(Rect(0, 0, resImg.cols, resImg.rows));
return cropImg;
}
return resImg;


}

Then i get error in line 34 above. OpencvError: Assertion failed (0 <=roi.x && 0 <= roi.width && ro.x + roi.width < m.cols && 0<=roi.height && roi.y + roi.height <= m.rows) in cv::Mat::Mat