OpenCV - How to apply adaptive threshold to an image on iOS

Question

I am trying to apply adaptive thresholding to an image of an A4 paper as shown below:

I use the c

Answer 1

Try this:

+ (UIImage *)processImageWithOpenCV:(UIImage*)inputImage {
    cv::Mat cvImage = [inputImage CVMat];
    threshold(cvImage, cvImage, 128, 255, cv::THRESH_BINARY);
    return [UIImage imageWithCVMat:cvImage];
}

Result image: