lit

Name

lit - Local Information Transform texture measure

Syntax

 #include <xite/median.h>

 int lit( IBAND input, IBAND output, int dx,
    int dy, int dp );

Description

lit filters the input band into the output band using a local filter with window size dx * dy. Even values of dx and dy are increased by one. Uses histogram updating when moving horizontally from pixel to pixel.

Algorithm: lit(x,y) is number of pixels inside the processing window (including the center pixel itself) with pixel value in the interval cp-dp..cp+dp, where cp is center pixel value.

If histogram values become larger than 255, the pixels receive the value 255.

Restrictions

input and output must have pixel type unsigned byte.

Reference

Lowitz, Gabriel E.: "Extracting the Local Information Content of a Spatial Image" in Proc. 7.ICPR, Montral, Canada, Aug. 1984, 1266-1268.

Return value

 0 => ok
 1 => bad pixel value input band
 2 => bad pixel value output band
 3 => bad dx value (less than 1 or greater than xsize)
 4 => bad dy value (less than 1 or greater than ysize)
 5 => bad dp value (less than 0 or greater than 255)

Author

Tor Lønnestad, BLAB, Ifi, UiO.

Id

$Id: lit.c,v 1.24 1997/01/10 16:09:29 svein Exp $