/// <summary>
/// <para>(Accord .NET internal call)</para>
/// The Variance filter replaces each pixel in an image by its
/// neighborhood variance. The end result can be regarded as an
/// border enhancement, making the Variance filter suitable to
/// be used as an edge detection mechanism.
/// </summary>
/// <param name="img">Image.</param>
/// <param name="radius">The radius neighborhood used to compute a pixel's local variance.</param>
/// <returns>Processed image.</returns>
internal static Image <Gray, byte> Variance(this Image <Gray, byte> img, int radius = 2)
{
return(VarianceExtensionsBase.Variance(img, radius));
}
