1Pampaintspill User Manual(0) Pampaintspill User Manual(0)
2
6 pampaintspill - smoothly spill colors into the background
7
10 pampaintspill [--bgcolor=color] [--wrap] [--all] [--downsample=number]
11 [--power=number] [filename]
12 Minimum unique abbreviations of option are acceptable. You may use
14 double hyphens instead of single hyphen to denote options. You may use
15 white space in place of the equals sign to separate an option name from
16 its value.
17
20 This program is part of Netpbm(1).
21 pampaintspill produces a smooth color gradient from all of the non-
23 background-colored pixels in an input image, effectively <q>spilling
24 paint</q> onto the background. pampaintspill is similar to pamgradient
25 but differs in the following characteristics:
26 · pampaintspill accepts any number of paint
30 sources (non-background-colored pixels), which can lie
31 anywhere
32 on the canvas. pamgradient accepts exactly
33 four paint sources, one in each corner of the image.
34 · pampaintspill requires an input image while
37 pamgradient generates a new image from
38 scratch.
39 · pampaintspill can produce tileable output and
42 can control how tightly the gradient colors bind to their
43 source
44 pixels.
45 Results are generally best when the input image contains just a few,
48 crisp spots of color. Use your drawing program's pencil tool — as
49 opposed to a paintbrush or airbrush tool — with a small nib.
50
53 --bgcolor=color
54 Explicitly specify the background color. color can be
56 specified using any of the formats accepted by the
57 ppm_parsecolor() library routine ⟨libppm.html#colorname⟩
58 such as red or #ff0000. If
59 --bgcolor is not specified, pampaintspill makes an
60 educated guess about the background color based on the
61 colors in the
62 image's corners.
63 --wrap
66 Allow gradients to wrap around image borders. That is, colors
68 that spill off the right side of the image reappear on the
69 left side of
70 the image and likewise for left/right, top/bottom, and
71 bottom/top. --wrap makes images tileable, which is nice
72 for
73 producing desktop backgrounds.
74 --all
77 Recolor all pixels, not just background pixels. Normally,
79 non-background-colored pixels in the input image appear
80 unmodified in
81 the output image. With --all, all pixels are colored
82 based on their distance from all of the (other) non-back‐
83 ground-colored
84 pixels.
85 --downsample=number
88 Ignore all but number non-background-colored pixels.
90 When a large number of pixels in the input image differ in
91 color from
92 the background, pampaintspill runs very slowly. The
93 --downsample option randomly selects a given number of
94 colored
95 pixels to use as paint sources for the gradients and
96 ignores the rest,
97 thereby trading off image quality for speed of execution.
98 --power=number
101 Control how color intensity changes as a function of the
103 distance from a paint source. The default value for number
104 is
105 -2.0, which means that intensity drops (because of the
106 minus sign) with
107 the square (because of the 2.0) of the distance from each
108 paint
109 source. -2.0 generally works well in practice, but other
110 values can be
111 specified for various special effects. With very small
112 numbers of paint
113 sources, -1.0 may produce subtler gradients, but these get
114 muddier as
115 the number of paint sources increases. Positive numbers
116 (e.g., 1.0 and
117 2.0) make the paint sources stand out in the output image
118 by pushing the
119 gradients away from them.
120
125 ·
126 pamgradient(1)
128 ·
130 ppmmake(1),
132 ·
134 ppmrainbow(1),
136 ·
138 pgmramp(1),
140 ·
142 ppmpat(1),
144 ·
146 pam(1)
148
152 pampaintspill was new in Netpbm 10.50 (March 2010).
153
157 Copyright © 2010 Scott Pakin, <a href=
158 "mailto:scott+pbm@pakin.org">scott+pbm@pakin.org</a>.
159netpbm documentation Pampaintspill User Manual(0)