Two-Dimensional Probability Functions of Morphological Dilation and Erosion of a Memoryless Source

This paper derives the two-dimensional probability distribution and density functions of morphological dilation and erosion of a one-dimensional memoryless source and reports numerical results for a uniform source, thus providing methodology for joint distributions for other morphological operations. The joint density functions expressed in closed forms contain the Dirac delta functions due to the joint discontinuity within the dilation and erosion. They also exhibit symmetry between these two morphological operations. Applications of the result can be found in the computation of the autocorrelation and the power spectral density functions of dilated and/or eroded sources, in the computation of other higher moments thereof, and in multidimensional quantization.