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=color]
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 1, 2, or 4 bits wide, or
44 color files 8 bits wide, so pnmtopalm automatically scales colors to
45 have an appropriate maxval, unless you specify a depth or max depth.
46 Input files must have an appropriate number and set of colors for the
47 selected output constraints.
48 This often means that you should run the PNM image through pnmquant or
50 pnmremap before you pass it to pnmtopalm. Netpbm comes with several
51 colormap files you can use with pnmremap for this purpose. They are
52 palmgray2.map (4 shades of gray for a depth of 2), palmgray4.map (16
53 shades of gray for a depth of 4), and palmcolor8.map (232 colors in
54 default Palm colormap). In a standard Netpbm installation, these are
55 in the Netpbm data directory, and you can find the Netpbm data direc‐
56 tory with a netpbm-config --datadir shell command.
57 Example:
59 pnmremap myimage.ppm \
61 -mapfile=$(netpbm-config --datadir)/palmgray2.map \
62 | pnmtopalm -depth=2 >myimage.palm
63 Palm Bitmap Version
68 pnmtopalm generates a Version 0, 1, 2, or 3 Palm Bitmap. It generates
69 the oldest (lowest) version it can for the given image and the options
70 you specify.
71 · If you specify a density (-density option) higher than 'low,'
75 the version is at least 3.
76 · If you specify transparency (-transparent option) or any com‐
79 pression, the version is at least 2.
80 · If you specify a custom colormap (-colormap option), the verison
83 is at least 1.
84 · If the image has more than one bit per pixel, the version is at
87 least 1. The image has more than one bit per pixel if you spec‐
88 ify it with -depth or if you let it default and the image has
89 more than two colors (or shades of gray).
90 All releases of Palm OS can read a Version 0 bitmap. Palm OS 3.0 and
94 later can read a Version 1 bitmap. Palm OS 3.5 and later can read a
95 Version 2 bitmap. To read a Version 3 bitmap, you need Palm OS Garnet
96 or a handheld running the High Density Display Feature Set.
97
100 -verbose
101 Display the format of the output file.
102 -depth=N
105 Produce a file of depth N, where N must be either 1, 2, 4, 8, or
106 16. Because the default Palm 8-bit colormap is not grayscale,
107 if the input is a grayscale or monochrome image, the output will
108 never be more than 4 bits deep, regardless of the specified
109 depth. Note that 8-bit color works only in PalmOS 3.5 (and
110 higher), and 16-bit direct color works only in PalmOS 4.0 (and
111 higher). However, the 16-bit direct color format is also com‐
112 patible with the various PalmOS 3.x versions used in the Hand‐
113 spring Visor, so these images may also work in that device.
114 -maxdepth=N
117 Produce a file of minimal depth, but in any case less than N
118 bits wide. If you specify 16-bit, the output will always be
119 16-bit direct color.
120 -offset
123 Set the nextDepthOffset field in the palm file header to indi‐
124 cate the end of the file (and pad the end of the file to 4
125 bytes, since nextDepthOffset can point only to 4 byte bound‐
126 aries).
127 A palm image file can contain multiple renditions of the same
129 image, with different color depths, so a viewer can choose one
130 appropriate for the display. The nextDepthOffset field tells
131 where in the stream the next rendition begins.
132 pnmtopalm creates a file that contains only one image, but you
134 can separately concatenate multiple one-image files to create a
135 multi-image file. If you do that, you'll need to use -offset so
136 that the resulting concatenation is a correct stream.
137 By default (if you don't specify -offset), pnmtopalm generates a
139 nextDepthOffset field that says there is no following image (and
140 does not add any padding after the image).
141 Version 3 Palm Bitmaps actually have a nextBitmapOffset field
143 instead of the nextDepthOffset. The foregoing applies to which‐
144 ever is relevant.
145 The -offset option was new in Netpbm 10.26 (January 2005).
147 Before that, pnmtopalm always set the nextDepthOffset field to
148 'none.'
149 Before Netpbm 10.27 (March 2005), you cannot use -offset if you
151 create a compressed raster (because pnmtopalm isn't smart enough
152 to be able to know the size of the image at the time it writes
153 the header). You also cannot use it with 16 bit color depth or
154 with the -colormap option, for much the same reason.
155 -withdummy
158 This option tells pnmtopalm to put in the stream, after after
159 the image, a dummy image header to introduce subsequent high
160 density images.
161 This dummy image header is a special sequence specified in Palm
163 Bitmap specifications. It looks to an older Palm Bitmap inter‐
164 preter like an invalid image header, so such an intepreter will
165 stop reading the stream there. But a new Palm Bitmap inter‐
166 preter recognizes it for what it is (just something to choke an
167 old interpreter) and skips over it. Presumably, you will add to
168 the stream after this high density images which would confuse an
169 older interpreter.
170 If you specify -withdummy, you must also specify -offset, since
172 it doesn't make any sense otherwise.
173 -withdummy was new in Netpbm 10.27 (March 2005).
175 -colormap
178 Build a custom colormap and include it in the output file. This
179 is not recommended by Palm, for efficiency reasons. Otherwise,
180 pnmtopalm uses the default Palm colormap for color output.
181 -transparent=color
184 Marks one particular color as fully transparent. The format to
185 specify the color is either (when for example orange)
186 '1.0,0.5,0.0', where the values are floats between zero and one,
187 or with the syntax '#RGB', '#RRGGBB' or '#RRRRGGGGBBBB' where R,
188 G and B are hexadecimal numbers. Transparency works only on
189 Palm OS 3.5 and higher.
190 -scanline-compression
193 Specifies that the output Palm bitmap will use the Palm scanline
194 compression scheme. Scanline compression works only in Palm OS
195 2.0 and higher.
196 -rle-compression
199 Specifies that the output Palm bitmap will use the Palm RLE com‐
200 pression scheme. RLE compression works only with Palm OS 3.5
201 and higher.
202 -packbits-compression
205 Specifies that the output Palm bitmap will use the Palm packbits
206 compression scheme. Packbits compression works only with Palm
207 OS 4.0 and higher.
208 This option was new in Netpbm 10.27 (March 2005).
210 -density=N
213 This specifies the Palm Bitmap density. The density is a number
214 that is proportional to the resolution the image should have
215 when displayed. The proportionality factor is up to whatever is
216 doing the displaying, but it's helpful to think of these numbers
217 as being pixels per inch. The allowable values are:
218 · 72
222 · 108
224 · 144
226 · 216
228 · 288
230 This option was new in Netpbm 10.27 (March 2005). Earlier
233 Netpbm could not generate Version 3 Palm Bitmaps, so there was
234 no such thing as density.
235
241 palmtopnm(1), pdbimgtopam(1), pnmquant(1), pnmremap(1), pnm(1)
242
246 Palm Bitmaps may contains multiple renditions of the same bitmap, in
247 different depths. To construct an N-multiple-rendition Palm Bitmap
248 with pnmtopalm, first construct renditions 1 through N-1 using the
249 -offset option, then construct the Nth image without the -offset
250 option. Then concatenate the individual renditions together in a sin‐
251 gle file using cat.
252 If you will include both high density and low density renditions, put
254 the high density images last and when you create the last of the low
255 density images, use the -withdummy option.
256 If you specify the Palm packbits compression scheme for a 16-bit direct
258 color bitmap, this program generates an invalid bitmap.
259
263 This program was originally written as ppmtoTbmp.c, by Ian Goldberg and
264 George Caswell. It was completely re-written by Bill Janssen to add
265 color, compression, and transparency function. Copyright 1995-2001 by
266 Ian Goldberg, George Caswell, and Bill Janssen.
267netpbm documentation 05 October 2003 Pnmtopalm User Manual(0)