The Entropy command computes the entropy of each layer of an image.

The entropy, , of a layer is computed by partitioning the intensities (values) of the pixels in the layer into  buckets, and then computing , where  is the probability that the intensity of a pixel falls in the -th bucket.

The img parameter specifies the image for which the entropy of the layers is computed.

The optional N parameter specifies the number of buckets per layer. The default is 256, which is usually suitable for images read from 8-bit per pixel per layer image files.

For a single layer (grayscale) image, the Entropy command returns a single value. For 3 or 4 layer images, a list is returned; the i-th element in the list is the entropy of the i-th layer.

autorange = truefalse

If true, set the range to the minimum and maximum values that occur in the image (on all layers).  Overrides the range option. The default is false.

range = numeric .. numeric

Assigns the range of values that the buckets cover. The default is 0.0 .. 1.0, which corresponds to the the range of values in an unprocessed image.