Canny Edge Detection

Modify the earlier ViewController.m file from this project:

//
//  ViewController.m
//  InstantOpenCv
//
//  Created by Paul Chin on 12/25/14.
//  Copyright (c) 2014 Paul Chin. All rights reserved.
//

#import "ViewController.h"

@interface ViewController ()

@end

@implementation ViewController

- (void)viewDidLoad {

    [super viewDidLoad];

    // Do any additional setup after loading the view, typically from a nib.
    //self.imageView.image=[UIImage imageNamed:@"StBernard.jpg"];

    

    UIImage *image = [UIImage imageNamed:@"StBernard.jpg"];
    UIImageToMat(image, cvImage);
    if(!cvImage.empty()){
        using namespace cv;
        Mat gray;
        cvtColor(cvImage, gray, CV_RGB2GRAY);//convert to single channel
        GaussianBlur(gray, gray, cvSize(5, 5),1.2,1.2);//remove small details

        

        Mat edges;
        Canny(gray, edges, 0, 50);  //detect edges
        cvImage.setTo(Scalar::all(255)); //fill image to white
        cvImage.setTo(Scalar(0,128,255,255),edges);//add edges

        

        self.imageView.image=MatToUIImage(cvImage);

    }
}

- (void)didReceiveMemoryWarning {

    [super didReceiveMemoryWarning];

    // Dispose of any resources that can be recreated.
    }

@end

Run the app on iOS simulator: