next up previous contents index
Next:   EXCHANGE Up: The KEYBOARD INTERFACE: Command Previous:   END GRAPHICS FILE

  ENTROPY

The histogram of pixel intensity values is calculated from -65535 to 65535 units. The raw data should be integer valued for this operation to be meaningful.

Calculates the zero order entropy of the ROI, and the theoretical maximum compression ratio compared to 16 bit raw storage which may be achieved by entropy encoding.

(Other information may also be output. This is being used to investigate and develop data compression algorithms.)



Andrew Hammersley
2004-01-09