virtual double Measure(const CImage& img) const
 {
     CImage fft = img.GetFFTImage();
     img.CopyMetadataTo(fft);
     
     cv::Size submatrixSize = cv::Size(ceil(img.cols * _radiusRatio), ceil(img.rows * _radiusRatio));
     cv::Point submatrixOrigin = cv::Point((img.cols - submatrixSize.width) / 2, (img.rows - submatrixSize.height) / 2);
     cv::Rect submatrixRect = cv::Rect(submatrixOrigin, submatrixSize);
     
     CImage imageCopy;
     img.copyTo(imageCopy);
     
     CImage roi = imageCopy(submatrixRect);
     roi.setTo(0);
     
     return cv::sum(imageCopy)[0];
 }