Possible methods of selecting of the threshold automatically.

Values of this enumeration:

• ClusteringKittler - Minimum error thresholding.
• ClusteringKMeans - See K-means clustering on Wikipedia .
• ClusteringOtsu - See Otsu method on Wikipedia. Fast and best method for most images.
• Entropy - Depends on image histogram's entropy. Best for images with only a few foreground pixels.
• HistogramIntermodes - Assuming the image histogram is bimodal, smooths it until there are only two local maxima and returns their average.