man > pampaintspill(1)

Pampaintspill User Manual(1)           General Commands Manual          Pampaintspill User Manual(1)

NAME
       pampaintspill - smoothly spill colors into the background


SYNOPSIS
       pampaintspill   [--bgcolor=color]   [--wrap]  [--all]  [--downsample=number]  [--near=number]
       [--power=number] [filename] [-randomseed=integer]

       Minimum unique abbreviations of option are acceptable.  You may use double hyphens instead of
       single hyphen to denote options.  You may use white space in place of the equals sign to sep‐
       arate an option name from its value.


DESCRIPTION
       This program is part of Netpbm(1).

       pampaintspill produces a smooth color gradient from all of the non-background-colored  pixels
       in  an input image, effectively "spilling paint" onto the background.  pampaintspill is simi‐
       lar to pamgradient but differs in the following characteristics:



       •      pampaintspill accepts any number of paint
                    sources (non-background-colored pixels), which can lie anywhere
                    on the canvas.  pamgradient accepts exactly
                    four paint sources, one in each corner of the image.


       •      pampaintspill requires an input image while
                    pamgradient generates a new image from
                    scratch.


       •      pampaintspill can produce tileable output and
                    can control how tightly the gradient colors bind to their source
                    pixels.


       Results are generally best when the input image contains just a few, crisp  spots  of  color.
       Use your drawing program's pencil tool - as opposed to a paintbrush or airbrush tool - with a
       small nib.


OPTIONS
       In  addition  to  the options common to all programs based on libnetpbm (most notably -quiet,
       see ]8;;index.html#commonoptions\ Common Options]8;;\ ), pampaintspill recognizes the following command line options:



       --bgcolor=color

              Explicitly specify the background color. color can be
                    specified using any of the  formats  accepted  by  the  ]8;;libnetpbm_image.html#colorname\pnm_parsecolor() library
              routine]8;;\  such as red or #ff0000.  If
                    --bgcolor is not specified, pampaintspill makes an
                    educated guess about the background color based on the colors in the
                    image's corners.


       --wrap

              Allow gradients to wrap around image borders. That is, colors
                    that spill off the right side of the image reappear on the left side of
                    the image and likewise for left/right, top/bottom, and
                    bottom/top. --wrap makes images tileable, which is nice for
                    producing desktop backgrounds.


       --all

              Recolor all pixels, not just background pixels. Normally,
                    non-background-colored pixels in the input image appear unmodified in
                    the output image. With --all, all pixels are colored
                    based on their distance from all of the (other) non-background-colored
                    pixels.


       --downsample=number

              Ignore all but number non-background-colored pixels.
                    When a large number of pixels in the input image differ in color from
                    the background, pampaintspill runs very slowly. The
                    --downsample option randomly selects a given number of colored
                    pixels to use as paint sources for the gradients and ignores the rest,
                    thereby trading off image quality for speed of execution.


       --near=number

              Consider only the nearest number paint sources when computing
                    a pixel's new color.  The default is to consider all paint sources.
                    In most cases, number should be fairly small, or its impact
                    will be minimal and execution time will increase unnecessarily.  A
                    value of 1 produces a coloring that looks a lot like a Voronoi
                    diagram.

              This option was new in Netpbm 10.97 (December 2021).


       --power=number

              Control how color intensity changes as a function of the
                    distance from a paint source. The default value for number is
                    -2.0, which means that intensity drops (because of the minus sign) with
                    the square (because of the 2.0) of the distance from each paint
                    source. -2.0 generally works well in practice, but other values can be
                    specified for various special effects. With very small numbers of paint
                    sources, -1.0 may produce subtler gradients, but these get muddier as
                    the number of paint sources increases. Positive numbers (e.g., 1.0 and
                    2.0) make the paint sources stand out in the output image by pushing the
                    gradients away from them.


       -randomseed=integer

              This is the seed for the random number generator that generates the
                pixels.

              Use this to ensure you get the same image on separate invocations.

              This option was new in Netpbm 10.94 (March 2021).




SEE ALSO
       •

              pamgradient(1)

       •

              ppmmake(1),

       •

              ppmrainbow(1),

       •

              pgmramp(1),

       •

              ppmpat(1),

       •

              pam(1)



HISTORY
       pampaintspill was new in Netpbm 10.50 (March 2010).



COPYRIGHT
       Copyright © 2010–2021 Scott Pakin, scott+pbm AT pakin.org.


Table Of Contents
       •

              ]8;;#synopsis\SYNOPSIS]8;;\

       •

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

       •

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

       •

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

       •

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

       •

              ]8;;#copyright\COPYRIGHT]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/pampaintspill.html

netpbm documentation                      02 November 2021              Pampaintspill User Manual(1)