1Pnmtopalm User Manual(0) Pnmtopalm User Manual(0)
2
6 pnmtopalm - convert a PNM image to a Palm Bitmap
7
10 pnmtopalm
11 [-verbose]
13 [-depth=N]
15 [-maxdepth=N]
17 [-colormap]
19 [-transparent=colorspec]
21 [-density=N]
23 [-offset]
25 [-withdummy] [-scanline_compression | -rle_compression | -packbits_com‐
27 pression]
28 [pnmfile]
30 Minimum unique abbreviation of option is acceptable. You may use dou‐
32 ble hyphens instead of single hyphen to denote options. You may use
33 white space in place of the equals sign to separate an option name from
34 its value.
35
38 This program is part of Netpbm(1).
39 pnmtopalm reads a PNM image as input, from Standard Input or pnmfile
41 and produces a Palm Bitmap as output.
42 Palm Bitmap files are either grayscale files with 1, 2, or 4 bits per
44 pixel, or mapped color files with 8 bit per pixel, or a direct color
45 file with 16 bits per pixel, and pnmtopalm chooses this color depth
46 based on the maxval and number of colors in the input, unless you spec‐
47 ify a depth (bits per pixel) with -depth. You can also specify a maxi‐
48 mum depth with -maxdepth to partially constrain pnmtopalm's choice.
49 Input files must have an appropriate number and set of colors for the
50 selected output constraints.
51 This often means that you should run the PNM image through pnmquant or
53 pnmremap before you pass it to pnmtopalm. Netpbm comes with several
54 colormap files you can use with pnmremap for this purpose. They are
55 palmgray2.map (4 shades of gray for a depth of 2), palmgray4.map (16
56 shades of gray for a depth of 4), and palmcolor8.map (232 colors in
57 default Palm colormap). In a standard Netpbm installation, these are
58 in the Netpbm data directory, and you can find the Netpbm data direc‐
59 tory with a netpbm-config --datadir shell command.
60 Example:
62 pnmremap myimage.ppm \
64 -mapfile=$(netpbm-config --datadir)/palmgray2.map \
65 | pnmtopalm -depth=2 >myimage.palm
66 Compressed Palm Bitmap files, at least the ones pnmtopalm knows how to
69 create, cannot have more than 8 bits per pixel. pnmtopalm defaults to
70 8 bits per pixel if you specify a compressed output. You can specify
71 the number of bits per pixel explicitly with -depth. -maxdepth has the
72 same effect as -depth. If you specify more than 8 bits per pixel with
73 either of these, pnmtopalm fails.
74 Palm Bitmap Version
77 pnmtopalm generates a Version 0, 1, 2, or 3 Palm Bitmap. It generates
78 the oldest (lowest) version it can for the given image and the options
79 you specify.
80 · If you specify a density (-density option) higher than "low,"
84 the version is at least 3.
85 · If you specify transparency (-transparent option) or any com‐
88 pression, the version is at least 2.
89 · If you specify a custom colormap (-colormap option), the version
92 is at least 1.
93 · If the image has more than one bit per pixel, the version is at
96 least 1. The image has more than one bit per pixel if you spec‐
97 ify it with -depth or if you let it default and the image has
98 more than two colors (or shades of gray).
99 All releases of Palm OS can read a Version 0 bitmap. Palm OS 3.0 and
103 later can read a Version 1 bitmap. Palm OS 3.5 and later can read a
104 Version 2 bitmap. To read a Version 3 bitmap, you need Palm OS Garnet
105 or a handheld running the High Density Display Feature Set.
106
109 In addition to the options common to all programs based on libnetpbm
110 (most notably -quiet, see
111 Common Options ⟨index.html#commonoptions⟩ ), pnmtopalm recognizes the
112 following command line options:
113 -verbose
117 Display the format of the output file.
118 -depth=N
121 Produce a file of depth N, where N must be either 1, 2, 4, 8, or
122 16. Because the default Palm 8-bit colormap is not grayscale,
123 if the input is a grayscale or monochrome image, the output will
124 never be more than 4 bits deep, regardless of the specified
125 depth. Note that 8-bit color works only in PalmOS 3.5 (and
126 higher), and 16-bit direct color works only in PalmOS 4.0 (and
127 higher). However, the 16-bit direct color format is also com‐
128 patible with the various PalmOS 3.x versions used in the Hand‐
129 spring Visor, so these images may also work in that device.
130 -maxdepth=N
133 Produce a file of minimal depth, but in any case less than N
134 bits wide. If you specify 16-bit, the output will always be
135 16-bit direct color.
136 -offset
139 Set the nextDepthOffset field in the palm file header to indi‐
140 cate the end of the file (and pad the end of the file to 4
141 bytes, since nextDepthOffset can point only to 4 byte bound‐
142 aries).
143 A palm image file can contain multiple renditions of the same
145 image, with different color depths, so a viewer can choose one
146 appropriate for the display. The nextDepthOffset field tells
147 where in the stream the next rendition begins.
148 pnmtopalm creates a file that contains only one image, but you
150 can separately concatenate multiple one-image files to create a
151 multi-image file. If you do that, you'll need to use -offset so
152 that the resulting concatenation is a correct stream.
153 By default (if you don't specify -offset), pnmtopalm generates a
155 nextDepthOffset field that says there is no following image (and
156 does not add any padding after the image).
157 Version 3 Palm Bitmaps actually have a nextBitmapOffset field
159 instead of the nextDepthOffset. The foregoing applies to which‐
160 ever is relevant.
161 The -offset option was new in Netpbm 10.26 (January 2005).
163 Before that, pnmtopalm always set the nextDepthOffset field to
164 "none."
165 Before Netpbm 10.27 (March 2005), you cannot use -offset if you
167 create a compressed raster (because pnmtopalm isn't smart enough
168 to be able to know the size of the image at the time it writes
169 the header). You also cannot use it with 16 bit color depth or
170 with the -colormap option, for much the same reason.
171 -withdummy
174 This option tells pnmtopalm to put in the stream, after the
175 image, a dummy image header to introduce subsequent high density
176 images.
177 This dummy image header is a special sequence specified in Palm
179 Bitmap specifications. It looks to an older Palm Bitmap inter‐
180 preter like an invalid image header, so such an interpreter will
181 stop reading the stream there. But a new Palm Bitmap inter‐
182 preter recognizes it for what it is (just something to choke an
183 old interpreter) and skips over it. Presumably, you will add to
184 the stream after this high density images which would confuse an
185 older interpreter.
186 If you specify -withdummy, you must also specify -offset, since
188 it doesn't make any sense otherwise.
189 -withdummy was new in Netpbm 10.27 (March 2005).
191 -colormap
194 Build a custom colormap and include it in the output file. This
195 is not recommended by Palm, for efficiency reasons. Otherwise,
196 pnmtopalm uses the default Palm colormap for color output.
197 -transparent=colorspec
200 Marks one particular color as fully transparent.
201 colorspec is as described for the argument of the
203 pnm_parsecolor() library routine
204 ⟨libnetpbm_image.html#colorname⟩ .
205 Transparency works only on Palm OS 3.5 and higher.
207 -scanline_compression
210 Specifies that the output Palm bitmap will use the Palm scanline
211 compression scheme. Scanline compression works only in Palm OS
212 2.0 and higher.
213 -rle_compression
216 Specifies that the output Palm bitmap will use the Palm RLE com‐
217 pression scheme. RLE compression works only with Palm OS 3.5
218 and higher.
219 -packbits_compression
222 Specifies that the output Palm bitmap will use the Palm packbits
223 compression scheme. Packbits compression works only with Palm
224 OS 4.0 and higher.
225 This option was new in Netpbm 10.27 (March 2005).
227 -density=N
230 This specifies the Palm Bitmap density. The density is a number
231 that is proportional to the resolution the image should have
232 when displayed. The proportionality factor is up to whatever is
233 doing the displaying, but it's helpful to think of these numbers
234 as being pixels per inch. The allowable values are:
235 · 72
239 · 108
241 · 144
243 · 216
245 · 288
247 This option was new in Netpbm 10.27 (March 2005). Earlier
250 Netpbm could not generate Version 3 Palm Bitmaps, so there was
251 no such thing as density.
252
257 palmtopnm(1), pdbimgtopam(1), pnmquant(1), pnmremap(1), pnm(1)
258
261 Palm Bitmaps may contains multiple renditions of the same bitmap, in
262 different depths. To construct an N-multiple-rendition Palm Bitmap
263 with pnmtopalm, first construct renditions 1 through N-1 using the
264 -offset option, then construct the Nth image without the -offset
265 option. Then concatenate the individual renditions together in a sin‐
266 gle file using cat.
267 If you will include both high density and low density renditions, put
269 the high density images last and when you create the last of the low
270 density images, use the -withdummy option.
271 If you specify the Palm packbits compression scheme for a 16-bit direct
273 color bitmap, this program generates an invalid bitmap.
274
278 This program was originally written as ppmtoTbmp.c, by Ian Goldberg and
279 George Caswell. It was completely re-written by Bill Janssen to add
280 color, compression, and transparency function. Copyright 1995-2001 by
281 Ian Goldberg, George Caswell, and Bill Janssen.
282
284 This manual page was generated by the Netpbm tool 'makeman' from HTML
285 source. The master documentation is at
286 http://netpbm.sourceforge.net/doc/pnmtopalm.html
288netpbm documentation 25 August 2017 Pnmtopalm User Manual(0)