The fraction of heterogeneous pixels remaining after an erosion.

A McHeterogeneity object.  

object.mRgnClumpiness

The mRgnClumpiness Property syntax has these parts:

mRgnClumpiness is derived from mRgnHeterogeneity. Heterogeonous pixels are those that vary by more than the McHeterogeneity.IntensityRange percent from the average intensity for the region (mRgnDensity).

For the mRgnClumpiness computation, all hetrogenerous pixels are marked as foreground in a temporary image. That image is then eroded using a 5 by 5 octagonal kernel. The ratio of the number of pixels surviving the erode compared to the number of hetrogenerous pixels is reported as the mRgnClumpiness value for each region.

Thus to have a non-zero clumpiness, the region must have fairly large connected areas (greater than about 6 by 6 pixels) of exceptionally bright and/or dark pixels. Subtly or finely textured regions will result in either no heterogeneous pixels of none that will survive the erosion.

The largest possible value of mRgnClumpiness approaches 1.0, but never reaches it, because even if all pixels in a region are hetrogenerous the erosion will remove some from the region's edges.

The measurement was originally described by

Young IT, Verbeek PW, and Mayall BH, Characterization of chromatin distribution in cell nuclei. Cytometry, 1986. 7: p. 467-474.

If you are measuring both mRgnHeterogeneity and mRgnClumpiness, you can increase efficiency by accessing the mRgnClumpiness McMeasure.Value first or by setting mRgnClumpiness.Enabled=True before accessing mRgnHeterogeneity.Value.