Documentation made easier
pampaintspill - smoothly spill colors into the background
pampaintspill [--bgcolor=color] [--wrap] [--all] [--downsample=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.
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 similar to pamgradient but differs in the following characteristics:
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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.
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pampaintspill requires an input image while |
pamgradient generates a
new image from
scratch.
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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.
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.
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--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.
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--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.
--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).
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pamgradient(1) |
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ppmmake(1), |
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ppmrainbow(1), |
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pgmramp(1), |
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ppmpat(1), |
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pam(1) |
pampaintspill was new in Netpbm 10.50 (March 2010).
Copyright © 2010 Scott Pakin, scott+pbm@pakin.org.
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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