vhisto(1)

PROGRAM
vhisto - Finds the histogram of the gray-levels of a real, single band, non-bit image.

SYNTAX

vhisto

-i  input image

-o  output ASCII file

[-m]
    mask image

[-l]
    lower bound

[-u]
    upper bound

[-n]
    number of bins

[-t]
    If True Take Log of Data Before Histogramming

[-p]
    If True Output Histogram in Percent

[-V]
    Gives the version for vhisto

[-U]
    Gives the usage for vhisto

[-P]
    Prompts for command line options

[-A [file1]]
    Creates the answer file called vhisto.ans or file1

[-a [file1]]
    Uses vhisto.ans or file1 as the answer file

DESCRIPTION
vhisto computes the histogram of a gray-level image.

The histogram values are written to an ASCII file in the form of pairs of data: lower bin bound and bin count.

REQUIRED ARGUMENTS

-i  type: infile
    desc: input image

-o  type: outfile
    desc: output ASCII file

OPTIONAL ARGUMENTS

-m  type: infile
    desc: mask image

-l  type: float
    desc: lower bound
    default: 0
    bounds: no range checking

-u  type: float
    desc: upper bound
    default: 256
    bounds: no range checking

-n  type: integer
    desc: number of bins
    default: 256
    bounds: value > 0

-t  type: boolean
    desc: If True Take Log of Data Before Histogramming
    default: false

-p  type: boolean
    desc: If True Output Histogram in Percent
    default: false

EXAMPLES
vhisto -i input.image -o output.image -m mask.image -l 0 -u 9 -n 10 -t 0 -p 1

This command takes the histogram of input.image and stores it in ascii format in file output.image. The mask file mask.image is used and only pixels corresponding to non-zero pixels in the mask are counted in the histogram. The lower bound of the histogram is 0 and the upper bound is 9. The histogram uses 10 cells. The option -t 0 specifies not to take the log of each pixel before including it in the histogram, and -p 1 specifies that the output histogram values will be expressed in terms of a percentage of the total number of pixels instead of an absolute count.

SEE ALSO
intro(1), verror(3), vgparms(3), vutils(3), lvhisto(3) lvhisto(3), vhsee(1)

RESTRICTIONS
vhisto only works with BYTE, SHORT, INT, and FLOAT data types.

COPYRIGHT
Copyright 1991, University of New Mexico. All rights reserved.