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Pammixmulti User Manual(1)  General Commands Manual Pammixmulti User Manual(1)

NAME
       pammixmulti - blend together multiple PAM images

SYNOPSIS
       pammixmulti
         [--blend=average|random|mask]
         [--maskfile=filename]
         [--stdev=number]
         [--randomseed integer]
         filename ...

       Minimum  unique  abbreviation of an option is acceptable. You can use a
       single hyphen instead of double hyphens to denote options. You can  use
       white space in place of the equals sign to separate an option name from
       its value.

DESCRIPTION
       This file is part of Netpbm(1).

       pammixmulti mixes two or more images to produce a new image.  The  pro-
       gram provides multiple ways to interpret "mix."

OPTIONS
       In  addition  to  the options common to all programs based on libnetpbm
       (most notably -quiet, see
        Common Options ⟨index.html#commonoptions⟩  ),  pammixmulti  recognizes
       the following command line options:

       --blend=average|random|mask

              This  option  specifies  how the input images should be mixed to
              produce the output image.  With --blend=average  (the  default),
              each  pixel  in  the  output is produced by averaging the corre-
              sponding pixels from all the input images.  With --blend=random,
              each  pixel  in  the  output is produced by selecting the corre-
              sponding pixel from one of the input images, chosen at random on
              a  per-pixel basis.  With --blend=mask, each pixel in the output
              is produced by a weighted average of  the  corresponding  pixels
              from all the input images based on the grayscale level of an ad-
              ditional mask image.

       --maskfile=filename

              In conjunction with --blend=mask, this option names a  grayscale
              mask  file  to control the blending of each pixel.  (If the file
              is not grayscale, the first channel is treated as gray).   Where
              the  mask  file is black, the first image is selected. Where the
              mask file is white, the last image  is  selected.   Intermediate
              levels of gray select intermediate images.

       --stdev=number

              When  used  with --blend=mask, this option controls how smoothly
              the various input images are mixed to produce each output pixel.
              For  example,  consider running pammixmulti with three input im-
              ages and a mask image that uses gray levels from 0 to 255. Given
              --stdev=0.0,  gray levels 0-84 produce exclusively image 1; gray
              levels 85-170 produce  exclusively  image  2;  and  gray  levels
              171-255 produce exclusively image 3.  If the argument to --stdev
              is positive, images are blended according to a normal  distribu-
              tion.  Hence, gray levels around 85 produce an output pixel that
              includes roughly equal amounts of the corresponding  pixel  from
              images 1 and 2 but less of the corresponding pixel from image 3.
              As number tends towards the number of input images (going beyond
              that has diminishing impact), the output tends to look more like
              --blend=average. number defaults to 0.25.

       --randomseed integer
              This is the seed for  the  random  number  generator  used  with
              --blend=random

              Use  this  to  ensure you get the same image on separate invoca-
              tions.

ARGUMENTS
       You supply the names of the files to mix as non-option arguments.

EXAMPLES
       Average a bunch of PPM images to produce a new PAM image:
           pammixmulti input*.ppm >output.ppm

       Mix these same images by taking each pixel from a randomly selected in-
       put image:

           pammixmulti --blend=random input*.ppm >output.ppm

       Use  a  mask image to control the fading among input images on a pixel-
       by-pixel basis:

           pammixmulti --blend=mask --maskfile=mask.pgm >output.pam \
              one.pam two.pam three.pam four.pam

       Do the same but with more abrupt transitions:

           pammixmulti --blend=mask --maskfile=mask.pgm --stdev=0.0 >output.pam \
              one.pam two.pam three.pam four.pam

       and now with more gradual transitions:

           pammixmulti --blend=mask --maskfile=mask.pgm --stdev=1.0 >output.pam \
              one.pam two.pam three.pam four.pam

HISTORY
       pammixmulti was new in Netpbm 10.85 (December 2018).

AUTHOR
       Copyright 2018 Scott Pakin, scott+pbm@pakin.org.

SEE ALSO
       pamcomp(1), ppmmix(1), pamarith(1), pnm(1), pam(1)

Table Of Contents
       •

              SYNOPSIS ⟨#synopsis⟩

       •

              DESCRIPTION ⟨#description⟩

       •

              OPTIONS ⟨#options⟩

       •

              ARGUMENTS ⟨#arguments⟩

       •

              EXAMPLES ⟨#examples⟩

       •

              HISTORY ⟨#history⟩

       •

              AUTHOR ⟨#author⟩

       •

              SEE ALSO ⟨#seealso⟩

DOCUMENT SOURCE
       This manual page was generated by the Netpbm tool 'makeman'  from  HTML
       source.  The master documentation is at

              http://netpbm.sourceforge.net/doc/pammixmulti.html

netpbm documentation           18 November 2018     Pammixmulti User Manual(1)

Generated by dwww version 1.15 on Sat Jun 29 02:40:01 CEST 2024.