man > pammixmulti(1)

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 program provides multiple
       ways to interpret "mix."



OPTIONS
       In addition to the options common to all programs based on libnetpbm  (most  notably  -quiet,
       see ]8;;index.html#commonoptions\ Common Options]8;;\ ), 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 im‐
              age.  With --blend=average (the default), each pixel in the output is produced by  av‐
              eraging the corresponding pixels from all the input images.  With --blend=random, each
              pixel  in  the output is produced by selecting the corresponding 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 additional 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  se‐
              lect intermediate images.



       --stdev=number

              When  used  with --blend=mask, this option controls how smoothly the various input im‐
              ages are mixed to produce each output pixel.  For example,  consider  running  pammix‐
              multi  with  three  input images 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 distrib‐
              ution.  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 corre‐
              sponding pixel from image 3.  As number tends towards the number of input images  (go‐
              ing  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 invocations.




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 input 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 AT pakin.org.


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



Table Of Contents
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              ]8;;#synopsis\SYNOPSIS]8;;\

       •

              ]8;;#description\DESCRIPTION]8;;\

       •

              ]8;;#options\OPTIONS]8;;\

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              ]8;;#arguments\ARGUMENTS]8;;\

       •

              ]8;;#examples\EXAMPLES]8;;\

       •

              ]8;;#history\HISTORY]8;;\

       •

              ]8;;#author\AUTHOR]8;;\

       •

              ]8;;#seealso\SEE ALSO]8;;\

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)