1Pamtosvg User Manual(0) Pamtosvg User Manual(0)
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6 pamtosvg - convert a Netpbm image to a SVG (Scalable Vector Graphics)
7 image
8
11 pamtosvg
12 [-background-color=colorname] [-centerline] [-corner-threshold=angle]
14 [-corner-always-threshold=angle] [-corner-surround=integer] [-tangent-
15 surround=integer] [-error-threshold=float] [-filter-iterations=count]
16 [-line-reversion-threshold=float] [-line-threshold=float] [-width-
17 weight-factor=float] [-preserve-width] [-remove-adjacent-corners]
18 [-log] [-report-progress] [pnmfile]
19 Minimum unique abbreviation of option is acceptable. You may use dou‐
21 ble hyphens instead of single hyphen to denote options. You may use
22 white space in place of the equals sign to separate an option name from
23 its value.
24
27 This program is part of Netpbm(1).
28 pamtosvg reads a PNM image as input and produce an SVG (Scalable Vector
30 Graphics) image as output. Thus, it traces curves in the input image
31 and creates a set of splines that represent the image.
32 SVG is a vector image format, which means it describes curves that com‐
34 pose an image. By contrast, PNM is a raster format, which means it
35 describes dots that compose an image. The main practical difference
36 between the two types is that you can scale vector images better. A
37 vector image also takes a lot less data to describe an image if the
38 image is composed of simple curves.
39 That means it is really an understatement to say that pamtosvg is an
41 image format converter. It's really an image tracer. Its main job is
42 to trace a raster image and find the lines in it. It then represents
43 its findings in SVG format.
44 pamtosvg does the same kind of thing that StreamLine, CorelTrace, and
46 Autotrace do. It is in fact derived from Autotrace.
47 SVG is a gigantic format, capable of amazing things. pamtosvg exploits
49 only a morsel of it. The SVG image produced by pamtosvg consists of a
50 single <svg> element, which has a 'width' attribute and a 'height'
51 attribute. The value of that element is composed of <path> elements.
52 That's it.
53 In the SVG output, distances are unitless, with one unit corresponding
55 to one pixel of the input.
56 So that pamtosvg will find simple curves in the image, you may want to
58 remove speckles from it with pbmclean and consolidate multiple shades
59 into single colors with pnmquant first.
60 For more information on SVG, see the Worldwide Web Consortium's SVG web
62 page ⟨http://www.w3.org/Graphics/SVG/⟩ .
63
67 -background-color=colorname
68 Treat the specified color as the background color and ignore it.
69 If you don't specify this option, pamtosvg does not recognize
71 any background color.
72 Specify the color (colorname) as described for the argument of
74 the ppm_parsecolor() library routine ⟨libppm.html#colorname⟩ .
75 -centerline
78 Trace an object's centerline.
79 By default, pamtosvg traces an object's outline.
81 -corner-always-threshold=angle
84 Consider any angle at a pixel which falls below angle angle (in
85 decimal floating point degrees) as a corner, even if it is bor‐
86 dered by other corner pixels. Default is 60 degrees.
87 -corner-surround=integer
90 Consider the specified number of pixels on either side of a
91 point when determining if that point is a corner. Default is 4.
92 -corner-threshold=angle
95 Consider any pixel which forms an angle with its predecessors
96 and successors that is smaller than angle (in decimal floating
97 point degrees) as a corner. Default is 100.
98 -error-threshold=float
101 Subdivide fitted curves that are offset by a number of pixels
102 exceeding the specified number. Default is 2.0.
103 -filter-iterations=integer
106 Smooth the curve the specified number of times prior to fitting
107 Default is 4.
108 -line-reversion-threshold=float
111 When a spline is closer to a straight line than the specified
112 real number weighted by the square of the curve length, maintain
113 it as a straight line, even if it is a list with curves.
114 Default is .01.
116 -line-threshold=float
119 If a spline does not deviate from the straight line defined by
120 its endpoints by more than the specified number of pixels, then
121 treat it as a straight line.
122 Default is 1.
124 -log Create a log of the curve tracing process (suitable for debug‐
127 ging). Put it in the file named inputfile.log in the current
128 directory, where inputfile is the root of the input file name,
129 or 'pamtosvg' if the input is from Standard Input or a file with
130 a weird name.
131 -preserve-width
134 Preserve line width prior to thinning. Meaningful only with
135 -centerline.
136 remove-adjacent-corners
139 Remove adjacent corners.
140 -report-progress
143 Report the progress of the tracing to Standard Error as it hap‐
144 pens.
145 -tangent-surround
148 Consider the specified number of points to either side of a
149 point when computing the tangent at that point. Default is 3.
150 -width-weight-factor
153 Weight factor for fitting the linewidth.
154
160 A convenient way to view an SVG document is with a web browser. Many
161 understand a file whose name ends in '.svg' to be an SVG image and can
162 render it.
163
167 pnmquant(1), pbmclean(1), pnm(1), Autotrace
168 ⟨http://autotrace.sourceforge.net⟩
169
172 pamtosvg was added to Netpbm in Version 10.33 (March 2006).
173 The core of pamtosvg -- the curve tracing logic -- was taken nearly
175 unmodified from Martin Weber's Autotrace program. That program dupli‐
176 cates a lot of Netpbm function, so pamtosvg is a much leaner program.
177 Bryan Henderson created pamtosvg, basically just by adapting Autotrace
179 to Netpbm.
180 Autotrace was first released in 2000 and updates were released through
182 2002. A number of people wrote the code in it, but Masatake Yamato and
183 Martin Weber appear to be the principal creators of it.
184 As of June 2006, there was a Sourceforge project
186 ⟨http://autotrace.sourceforge.net⟩ for it.
187netpbm documentation 23 April 2006 Pamtosvg User Manual(0)