
verrdif(1)                   Khoros                    verrdif(1)

PROGRAM
     verrdif - Perform dithering by four-direction error diffu-
     sion.

SYNTAX
     verrdif

     -i             input image filename

     -o             output image filename

     [-V]           Gives the version for verrdif

     [-U]           Gives the usage for verrdif

     [-P]           Prompts for command line options

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

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

DESCRIPTION
     verrdif performs a dithering operation using four-direction
     error diffusion.  This dither produces images that are easy
     on the eyes up close.  They also have good greyscale from
     far away, except when the image has slowly varying inten-
     sity.  In that case, some peculiar patterns may appear.
     This particular implementation of the error diffusion has
     been tuned to give nice results for non-synthetic (i.e.
     non-raytraced, etc) images.  Synthetic images look better
     with one of the ordered dithers.

     The output file is of type BIT, suitable for sending to the
     laser printer using one of the Khoros printing (hardcopy)
     routines.

REQUIRED ARGUMENTS
     -i     type: infile
            desc: input image filename

     -o     type: outfile
            desc: output image filename

OPTIONAL ARGUMENTS
     none

EXAMPLES
     verrdif -i ball.xv -o dith_ball.xv

     This will perform a dithering by error diffusion of the
     input image, saving the resulting image in dith_ball.xv.

SEE ALSO
     intro(1), verror(3), vgparms(3), vutils(3), lverrdif(3)

RESTRICTIONS
     verrdif operates only on BYTE data storage type images.

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

Khoros                    Release: 1.0                          1

