testing_noise_detection.cpp

float *luminance = new float[width * height];
float *blurredLuminance = new float[width * height];
float *tmpBuffer = new float[width * height];

for (int i = 0; i < pixelsCount; ++i) {
    luminance[i] = Spectrum(img + i * 3).Y();
    blurredLuminance[i] = luminance[i];
}

const float weight = 1.f;
GaussianBlur3x3FilterPlugin::ApplyBlurFilter<float>(width, height, 
    blurredLuminance, tmpBuffer, weight, 1.f, weight);

for (int i = 0; i < pixelsCount; ++i) {
    // The heart of the algorithm
    const float diff = fabsf(logf(blurredLuminance[i]) - logf(luminance[i]));

    diffVector[i] = diff;
    maxError = Max(maxError, diff);
    if (diff > threshold) ++todoPixelsCount;
}

delete[] luminance;
delete[] blurredLuminance;

GaussianBlur3x3FilterPlugin::ApplyBlurFilter<float>(width, height, 
    &diffVector[0], tmpBuffer, weight, 1.f, weight);

delete[] tmpBuffer;