Table 2.

Texture parameters and the formulae derived from gray level run length matrix

Run-length matrix parameters	Formulae
Short runs emphasis (SRE)	1/S S r (j | θ)/j2
Long runs emphasis (LRE)	1/S S r (j | θ) j2
Gray level non-uniformity (GLN)	1/S S g (i | θ)2
Run-length non-uniformity (RLN)	1/S S r (j | θ)2
Run percentage (RP)	1/n S r (j | θ)
Low gray level run emphasis (LGRE)	1/S S g (i | θ)/i2
High gray level run emphasis (HGRE)	1/S S i2 g (i | θ)

p (i, j | θ) is the (i, j)^th element of the run length matrix for a direction θ, G is the number of gray levels, R is the longest run, n is the number of pixels in the image, S is the total number of runs in the image.