Marcelo's profile - activity

Hello berak,

The preprocessing in training images and the input image are the same?

In my work, I use graysacale, CLAVE and Bilateral Filter, in the training images (100 images) and also on input image (webcam) but I'm getting bad results.

Have a suggestion?

Regards and sorry my english. Marcelo Porto Alegre/Brasil

ok...Thanks

Thank you so much berak,

I finally understand these functions.

If you can help me a little more, can you talk what the best metric for face recognize, because de confidence and the L2 error and cannot work properly.

Thanks, Marcelo

Thanks berak!

Could you explain, in mathematical words, Confidence and Prediction. These values use K-Nearest Neighbors, Euclidean Distance? If yes...How work?

Thanks, Marcelo

The code is this:

// Compare two images by getting the L2 error (square-root of sum of squared error).
double getSimilarity(const Mat A, const Mat B)
{
    if (A.rows > 0 && A.rows == B.rows && A.cols > 0 && A.cols == B.cols) {
        // Calculate the L2 relative error between the 2 images.
        double errorL2 = norm(A, B, CV_L2);
        // Convert to a reasonable scale, since L2 error is summed across all pixels of the image.
        double similarity = errorL2 / (double)(A.rows * A.cols);
        return similarity;
    }
    else {
        //cout << "WARNING: Images have a different size in 'getSimilarity()'." << endl;
        return 100000000.0;  // Return a bad value
    }
}

If L2 relative error is a Euclidean Distance, what is this "Predict" and "Confidence" in opencv FaceRecognizer class?

Regards, Marcelo

Thanks for help.

I can't a link to download, only a github page: https://github.com/MasteringOpenCV/code/blob/master/Chapter8_FaceRecognition/recognition.cpp

Hello,

I'm studying opencv for facial recognition and I read about L2 relative error in "Mastering OpenCV book". What is L2 relative error? Is classical formula or a new proposed formula?

Regards, Marcelo