INTHIST = VL_INTHIST(LABELS) computes the integral histogram for the label map(s) LABELS.
LABELS is a [M,N,L] UINT32 array containing L label maps (one for each MxN layer). Each label map associates to each of the MxN pixels one of K labels (a value of 0 denotes no association) with unitary mass.
INTHIST is the [M,N,K] integral histogram obtained by integrating the label maps (an integral histogram is just an array of K integral images, one for each of the K labels). All layers of labels are accumulated to the same integral histogram.
The total number of labels K is obtained as the maximum value of LABELS. VL_INTHIST(..., 'NUMLABELS', K) specifies the number of labels explicitly.
VL_INTHIST(..., 'MASS', MASSES) specifies a mass MASSES for each entry of LABELS. MASSES can be either of class UINT32 or DOUBLE, and the class of INTHIST varies accordingly.
See also: VL_IMINTEGRAL(), VL_SAMPLEINTHIST(), VL_HELP().