TPB's profile - activity

Thank your for your answer.

This code actually is working right now though. Isn't the float just rounded so it will fit?

To make it explicit, is this correct?

destPix[j][0] =(int) *centroidPtr++;

What file are you trying to open?

There is a pre-compiled OpenCV.framework for ios, but you don't "open" that you import it into an XCode project.

If it is a OSX app you are trying to open, you need to change your security preferences as the dialog suggests.

System Preferences > Security & Privacy > General >Allow apps downloaded from > Select Anywhere (unlock and enter password if necessary).

Hello,

I know this has been asked many times and I've gone over the docs here but cannot seem to find an answer to my specific issue. I am trying to map the results from k-means clustering back into an image with reduced colors.

My old code works and does this using the Mat.at accessor, but it is very slow. I am trying to re-write this using pointers to improve performance, but right now the clustered image has many diagonal lines and the colors/pixels are not in the right place.

This works but is slow

for( int y = 0; y < resized.rows; y++ ){
    for( int x = 0; x < resized.cols; x++ ){
        {
            pixelPos =y + x*resized.rows;
            cluster_idx = labels.at<int>(pixelPos,0);
            clusteredImg.at<Vec3b>(y,x)[0] = centers.at<float>(cluster_idx, 0);
            clusteredImg.at<Vec3b>(y,x)[1] = centers.at<float>(cluster_idx, 1);
            clusteredImg.at<Vec3b>(y,x)[2] = centers.at<float>(cluster_idx, 2);
        }
    }

}

EDIT: The below code is working I had a silly mistake where I forgot that labels was M*Nx1 rather than MxNx1.

If there is any room for improvement please let me know!

for (int i = 0; i < resized.rows; ++i)
{
    cv::Vec3b* destPix = clusteredImg.ptr<cv::Vec3b>(i);
    int* labelPix = labels.ptr<int>(i);
    for (int j = 0; j < resized.cols; ++j)
    {
        pixelPos = i + j*resized.rows;
        cluster_idx = *labels.ptr<int>(pixelPos,0);
        float * centroidPtr = centers.ptr<float>(cluster_idx);

        destPix[j][0] = *centroidPtr++;
        destPix[j][1] = *centroidPtr++;
        destPix[j][2] = *centroidPtr++;
    }
}

Sorry if this is a stupid question, I am very new to C++.

I'm sure I have something wrong with how the destination data is assigned. I've checked the source data by printing debug statements and that seems to be correct.