The Spectral Difference Segmentation algorithm merges neighboring image objects ac-
cording to their mean image layer intensity values. Neighboring image objects are
merged if the difference between their layer mean intensities is below the value given
by the maximum spectral difference.
This algorithm is designed to refine existing segmentation results, by merging spectrally
similar image objects produced by previous segmentations. It cannot be used to create
new image object levels based on the pixel level domain.