pampaintspill

Langue: en

Version: 370984 (fedora - 01/12/10)

Section: 1 (Commandes utilisateur)

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pampaintspill - smoothly spill colors into the background

SYNOPSIS

pampaintspill [--bgcolor=color] [--wrap] [--all] [--downsample=number] [--power=number] [filename]

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, effectively <q>spilling paint</q> 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 &mdash; as opposed to a paintbrush or airbrush tool &mdash; with a small nib.

OPTIONS

--bgcolor=color

   Explicitly specify the background color. color can be
      specified using any of the formats accepted by the  ppm_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 --allall 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.
--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.

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 © 2010 Scott Pakin, <a href= "mailto:scott+pbm@pakin.org">scott+pbm@pakin.org</a>.