Manual: pampaintspill

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 separate 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,	 ef‐
       fectively "spilling paint" onto the background.	pampaintspill is similar 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  Common Options ),
       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 pnm_parsecolor() library	      routine  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@pakin.org.

Table Of Contents
       •      SYNOPSIS

       •      DESCRIPTION

       •      OPTIONS

       •      SEE ALSO

       •      HISTORY

       •      COPYRIGHT

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)