1Ppmtoarbtxt User Manual(0) Ppmtoarbtxt User Manual(0)
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6 ppmtoarbtxt - generate image in arbitrary text format from PPM image
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10 ppmtoarbtxt bodytmpl [-hd headtmpl] [-tl tailtmpl] [ppmfile]
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14 This program is part of Netpbm(1).
15 ppmtoarbtxt generates simple text-based graphics formats based on for‐
17 mat descriptions given as input. A text-based graphics format is one
18 in which an image is represented by text (like PNM plain format, but
19 unlike PNM raw format).
20 ppmtoarbtxt reads a PPM image as input. For each pixel in the image,
22 ppmtoarbtxt writes the contents of the template file bodytmpl, with
23 certain substitutions based on the value of the pixel, to Standard Out‐
24 put.
25 You may also supply a head template file, in which case ppmtoarbtxt
27 generates text from the template file, based on the image dimensions,
28 and includes it in the output before anything else.
29 Likewise, you may supply a tail template file to cause text to be
31 placed at the end of the output.
32 Template Files
36 The text that ppmtoarbtxt generates from a template file is the literal
37 text of the template file, except with substitution specifier replaced
38 with something else. The program recognizes a substitution specifier
39 as text of the form #(...).
40 ppmtoarbtxt treats white space in the template files the same as any
42 other characters, placing it in the output, with one exception: If the
43 template file ends with a newline character, ppmtoarbtxt ignores it --
44 it does not include it in the output.
45 Many substitution specifiers use format strings (another form of tem‐
47 plate) to specify the substitution. You should make these format
48 strings as minimal as possible, placing literal text outside the sub‐
49 stitution specifier instead of inside the format string. For example,
50 Wrong: #(flum %%%2.2f 0 1)
52 Right: %#(flum %2.2f 0 1)
54 The valid substitution specifiers are as follows. Text that has the
56 form of a substitution specifier but is not actually valid (e.g.
57 #(random junk) usually just specifies its literal value, but if it is
58 close enough to something valid, ppmtoarbtxt assumes you made a mistake
59 and fails.
60 Useful in a body template, to do substitutions based on a particular
62 pixel:
63 #(ired format blackref whiteref)
67 generates an integer in the range blackref to whiteref in a for‐
68 mat specified by format representing the red intensity of the
69 pixel. A red intensity of 0 becomes blackref; a red intensity
70 of maxval becomes whiteref, with the rest linearly interpolated
71 in between.
72 format is a printf-like format specifier like "%d". ppmtoarbtxt
74 uses as the entire format string to a fprintf POSIX library call
75 whose only other argument is the red itensity as an integer data
76 type. ppmtoarbtxt does not necessarily verify that your format
77 string makes sense; there are values you could specify that
78 could even crash the program. To avoid unexpected behavior,
79 keep format strings simple and hardcoded, and never include a
80 per cent sign or newline.
81 #(ired) is equivalent to #(ired %d 0 255).
83 #(igreen format blackref whiteref)
86 Same as #(ired..., but for green.
87 #(iblue format blackref whiteref)
90 Same as #(ired..., but for blue.
91 #(ilum format blackref whiteref)
94 Same as #(ired..., but representing the luminance value
95 (0.299*red + 0.587*green + 0.114*blue) of the pixel.
96 #(fred format blackref whiteref)
99 Same as #(ired..., but generates a floating point number instead
100 of an integer.
101 In this case, the second argument to the fprintf that uses for‐
103 mat has a double precision floating point data type.
104 #(fred) is equivalent to #(fred %f 0.0 1.0).
106 #(fgreen format blackref whiteref)
109 Same as #(fred..., but for green.
110 #(fblue format blackref whiteref)
113 Same as #(fred..., but for blue.
114 #(flum format blackref whiteref)
117 Same as #(fred..., but representing the luminance value
118 (0.299*red + 0.587*green + 0.114*blue) of the pixel.
119 #(posx format)
122 Generates the horizontal position of the pixel, in pixels from
123 the left edge of the image.
124 The second argument to the fprintf that uses format has an
126 unsigned integer data type.
127 format defaults to %u
129 #(posy format)
132 Same as #(width..., but for the vertical position.
133 If you use any of the above substitution specifiers in a head or tail
137 template, the result is undefined.
138 Useful in a head or tail template, to do substitutions based on whole-
140 image attributes:
141 #(width format)
145 Generates the width in pixels of the image.
146 The second argument to the fprintf that uses format has an
148 unsigned integer data type.
149 format defaults to %u
151 #(height format)
154 Same as #(width..., but for the height of the image.
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161 -hd headtmpl
162 This option specifies a head template (headtmpl is the name of
163 the head template file); it causes ppmtoarbtxt to place the con‐
164 tents of the file named headtmpl at the beginning of the output
165 -tl tailtmpl
168 This option specifies a tail template; it is analogous to -hd.
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174 gray inversion
175 Here we generate a PGM plain-format image with gray inversion (like
176 ppmtopgm | pnminvert).
177 Contents of our head template file:
179 P2
181 #(width) #(height)
182 255
183 Contents of our body skeleton file:
185 #(ilum %d 255 0)
187 povray file
190 Here we generate a povray file where each pixel is represented by a
191 sphere at location (x,y,z) = (posx,height-posy,luminance). The color
192 of the sphere is the color of the pixel.
193 Contents of our head skeleton:
195 #include "colors.inc"
197 #include "textures.inc"
198 camera {
199 location <#(width) * 0.6, #(height) * 0.7, 80>
200 look_at <#(width) * 0.5, #(height) * 0.5, 0>
201 }
202 light_source { <#(width) * 0.5, #(height) * 0.5, 25> color White
204 }
205 Contents of our body skeleton:
207 sphere { <#(posx),#(height)-#(posy),#(ilum %d 0 10)>, 0.5
209 texture {
210 pigment {
211 color rgb <#(fred),#(fgreen),#(fblue)>
212 }
213 finish {
214 phong 1
215 }
216 }
217 }
218
221 pnmtoplainpnm(1) pamtable(1) ppm(1)
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225 ppmtoarbtxt was added to Netpbm in Release 10.14 (March 2003). It
226 existed under the name ppmtotxt since 1995.
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230 Copyright (C) 1995 by Peter Kirchgessner
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233 This manual page was generated by the Netpbm tool 'makeman' from HTML
234 source. The master documentation is at
235 http://netpbm.sourceforge.net/doc/ppmtoarbtxt.html
237netpbm documentation 26 November 2014 Ppmtoarbtxt User Manual(0)