How to determine an image is dark or not enough brightness?

[dev-ptdi]

I use C# code below to determine an image is dark or not enough brightness, how to do this with Magick.Net?

            Bitmap bitmap = new Bitmap(_filename);

            var colors = new List<Color>();
            for (int x = 0; x < bitmap.Size.Width; x++)
            {
                for (int y = 0; y < bitmap.Size.Height; y++)
                {
                    colors.Add(bitmap.GetPixel(x, y));
                }
            }

            float _calc_brightness = colors.Average(color => color.GetBrightness());

[dlemstra]

You could do that like this:

using (var image = new MagickImage(_filename))
{
    double _calc_brightness = image.Statistics().Composite().Mean;
}

[dev-ptdi]

Hi but the result is big different?

mine was : 0.12821941 but now I got 8273.42193287037

[dev-ptdi]

I need to determine an image is dark or blurry..

[dlemstra]

If you need a value between 0.0 and 1.0 you will need to use: (1.0 / Quantum.Max) * _calc_brightness. That will probably help you determine if the image is dark but I have no idea how you could use this to determine if an image is blurry.