Question

I’m attempting to convert a UIImage to a cv::Mat and then back to a UIImage and insert that UIImage into a UIImageView.

This is the code I’m using to convert:

UIImage * imageFromMat(const cv::Mat& cvMat){
NSData *data = [NSData dataWithBytes:cvMat.data length:cvMat.elemSize() * cvMat.total()];

CGColorSpaceRef colorSpace;

if (cvMat.elemSize() == 1) {
    colorSpace = CGColorSpaceCreateDeviceGray();
} else {
    colorSpace = CGColorSpaceCreateDeviceRGB();
}

CGDataProviderRef provider = CGDataProviderCreateWithCFData((__bridge CFDataRef)data);

CGImageRef imageRef = CGImageCreate(cvMat.cols,                                
                                    cvMat.rows,                                 
                                    8,                                           
                                    8 * cvMat.elemSize(),                          
                                    cvMat.step[0],                                
                                    colorSpace,                                   
                                    kCGImageAlphaNone | kCGBitmapByteOrderDefault,   
                                    provider,                                        
                                    NULL,                                         
                                    false,                                         
                                    kCGRenderingIntentDefault);                  

UIImage *image = [[[UIImage alloc] initWithCGImage:imageRef] autorelease];
CGImageRelease(imageRef);
CGDataProviderRelease(provider);
CGColorSpaceRelease(colorSpace);

return image;

}

It converts fine but as soon as I insert it into a UIImageView, I get a crash, so I’m assuming the problem lies there.

I’ve noticed that if I retain the original image(the one before converting to cv::Mat) the crash doesn’t happen, but I get a leak.

Any thoughts on what the problem could be?

Answer 1

Turns out I was over releasing CGImageRef.