xcode ios opencv memory leak. App is crashing - ios

Question

I am currently working on iOS with openvc,
I am trying to convert an cv::Mat to an UIImage.
But the app is crashing after a few seconds!
(Terminated due to Memory Error)
This is my code that I am currently using:
using namespace cv;
#import "ViewController.h"
#interface ViewController ()
#end
#implementation ViewController
{
CvVideoCamera* videoCamera;
CADisplayLink*run_loop;
UIImage*image2;
}
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
videoCamera = [[CvVideoCamera alloc] initWithParentView:_liveview];
videoCamera.defaultAVCaptureDevicePosition = AVCaptureDevicePositionBack;
videoCamera.defaultAVCaptureSessionPreset = AVCaptureSessionPresetiFrame1280x720;
videoCamera.defaultAVCaptureVideoOrientation = AVCaptureVideoOrientationLandscapeLeft;
videoCamera.defaultFPS = 30;
videoCamera.delegate = self;
[videoCamera start];
run_loop = [CADisplayLink displayLinkWithTarget:self selector:#selector(update)];
[run_loop setFrameInterval:2];
[run_loop addToRunLoop:[NSRunLoop currentRunLoop] forMode:NSRunLoopCommonModes];
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
- (void)update{
_smallliveview.image = image2;
}
- (UIImage *)UIImageFromMat:(cv::Mat)image
{
cvtColor(image, image, CV_BGR2RGB);
NSData *data = [NSData dataWithBytes:image.data length:image.elemSize()*image.total()];
CGColorSpaceRef colorSpace;
if (image.elemSize() == 1) {
colorSpace = CGColorSpaceCreateDeviceGray();
} else {
colorSpace = CGColorSpaceCreateDeviceRGB();
}
CGDataProviderRef provider = CGDataProviderCreateWithCFData((CFDataRef)data);//CGDataProviderCreateWithCFData((__bridge CFDataRef)data);
// Creating CGImage from cv::Mat
CGImageRef imageRef = CGImageCreate(image.cols, //width
image.rows, //height
8, //bits per component
8 * image.elemSize(), //bits per pixel
image.step.p[0], //bytesPerRow
colorSpace, //colorspace
kCGImageAlphaNone|kCGBitmapByteOrderDefault,// bitmap info
provider, //CGDataProviderRef
NULL, //decode
false, //should interpolate
kCGRenderingIntentDefault //intent
);
// Getting UIImage from CGImage
UIImage *finalImage = [UIImage imageWithCGImage:imageRef];
//[self.imgView setImage:finalImage];
CGImageRelease(imageRef);
CGDataProviderRelease(provider);
CGColorSpaceRelease(colorSpace);
return finalImage;
}
#pragma mark - Protocol CvVideoCameraDelegate
#ifdef __cplusplus
- (void)processImage:(Mat&)image;
{
image2 = [self UIImageFromMat:image];
}
#endif
#end
What should i do?
It would be very nice if somebody can help me!? (;
Greetings David

Answer 1

Throw away every bit of what you wrote to create a UIImage and use the MatToUIImage() function instead. Simply pass the mat to the function, and you have your image.
Although you didn't ask, you shouldn't use a run loop or display link here. Time and initiate related methods to the processImage method called by OpenCV.
Also, make sure you're using the latest version. This has nothing to do with your problem, but it's good practice.
To import OpenCV 3 into your Xcode 8 project:
Install 'OpenCV2' with Cocoapods (it says '2', but it's still version 3). Don't install the 'devel' build.
Open your project in the workspace Cocoapods created for you — not the project file you created — and append every implementation file that uses OpenCV with .mm (versus .m). You'll get strange error messages if you don't.