vhisteq − histogram equalization and other functions

vhisteq if=infile [of=outfile] [-equ] [-lin] [-log] [-exp] [fmin=xxx] [fmax=yyy] [-z]

Vhisteq computes a histogram equalized version of a byte image. It can also perform several other pixel transformations. For example:

vhisteq if=infile of=outfile -lin fmin=25 fmax=200

Creates outfile which is the input linearly mapped into the range 25 to 200)

A histogram equalization (option -equ)is performed by default. Fmin and fmax are used for the linear and logarithmic transforms. The exponential transform uses fmax only. Fmin and fmax default to 0 and 255 respectively.

vhisteq only accepts single channel byte images

-z

the -z option specifies that bin zero of the histogram is set to zero. This is useful for the histogram equalization of segmented images.

-lin

Compute a linear transform of the image

-log

Compute a log transform of the image

-exp

Compute an exponential transform of the image

fmin=

Set the min value of the output

fmax=

Set the max value of the output

A.P.Reeves, Gary Ross and Ben Burley