NAME¶
ppmtolss16 — Convert a PPM to an LSS16 image
SYNOPSIS¶
ppmtolss16 [
#rrggbb=
i ...] [< input.ppm]
[> output.rle]
DESCRIPTION¶
This manual page documents briefly the
ppmtolss16 command.
The
ppmtolss16 program converts a "raw" PPM file with max 16
colors to a simple RLE-based format:
simple RLE-based format
| unint32 0x1413f3d |
magic (littleendian) |
| unint16 xsize |
littleendian |
| unint15 ysize |
littleendian |
| 16 x unint8 r,g,b |
color map |
Color map is in 6-bit format (each byte is 0..63)
Then, a sequence of nybbles:
N ... if N is != previous pixel, one pixel of color N, otherwise run sequence
follows ...
M ... if M > 0 then run length is M+1, otherwise run sequence is encoded in
two nybbles, littleendian, +17
The nybble sequences are on a per-row basis, runs may not extend across rows and
odd-nybble rows are zero-padded.
At the start of a row, the "previous pixel" is assumed to be zero.
OPTIONS¶
A summary of options is included below.
- #rrggbb=i
- Specify that the color #rrggbb (hex) should be assigned index i (decimal).
BUG¶
This program cannot handle comments in the header, nor "plain" ppm
format.
SEE ALSO¶
ppmtolss16(1)
AUTHOR¶
This manual page was compiled by dann frazier <dannf@debian.org> for the
Debian GNU/Linux system (but may be used by others). Most of the
content was written by H. Peter Anvin.
