RTextureMetrics (version 1.1)

calcHOM: HOM Homogeinity

Description

calculates HOMOGENEITY measure for Grey Level co-occurrence matrices

Usage

calcHOM(rawmat)

Arguments

rawmat

assigns the GLC-Matrix to use

Value

• returns Homogeneity value

Details

Homogeneity weigths values by the inverse of the Contrast weight with weights decreasing exponentially away from diagonal Homogeneity measure is sometimes also called 'Inverse Difference Moment'.

References

Toennies, D., 2005: Grundlagen der Bildverabeitung, 341 S., Pearson Studium Harralick, R.M., Shanmugam, K., Dinstein, I., 1973: Textural Features for image classification. IEEE Transactions on Systems, Man and Cybernetics, SMC vol. 3 no. 6, pp. 610-620.

See Also

GLCM Tutorial by Mryka-Hall-Beyer, http://www.fp.ucalgary.ca/mhallbey/homogeneity.htm

Examples

data<-c(0,0,1,1,0,0,1,1,0,2,2,2,2,2,3,3)
mat<-matrix(data, nrow=4, byrow=TRUE)
(mat)
GLCM<-genGLCM(2,1,mat)
(GLCM)
(calcHOM(GLCM))
##-- ==>  Define data, use random,
##--	or do  help(data=index)  for the standard data sets.

## The function is currently defined as
function (rawmat) 
{
    size <- dim(rawmat)[1]
    mathomweights <- matrix(0, nrow = size, ncol = size)
    for (i in 1:size) {
        for (a in 1:size) {
            mathomweights[i, a] <- 1/(1 + (a - i)^2)
        }
    }
    hom <- rawmat * mathomweights
    return(sum(hom))
  }