spottopgm(1)
NAME
spottopgm - convert SPOT satellite images to Portable
Greymap format
SYNTAX
spottopgm [-1|2|3] [Firstcol Firstline Lastcol Lastline]
inputfile
OPTIONS
- -1|2|3 Extract the given colour from the SPOT image. The
- colours are infra-red, visible light and ultraviolet, although I don't know which corresponds to
which number. If the image is in colour, this will
be announced on standard error. The default colour
is 1. - Firstcol Firstline Lastcol Lastline
- Extract the specified rectangle from the SPOT
image. Most SPOT images are 3000 lines long and
3000 or more columns wide. Unfortunately the SPOT
format only gives the width and not the length.
The width is printed on standard error. The
default rectangle is the width of the input image
by 3000 lines.
DESCRIPTION
Spottopgm converts the named inputfile into Portable
Greymap format, defaulting to the first color and the
whole SPOT image unless specified by the options.
INSTALLATION
You must edit the source program and either define
BIG_ENDIAN or LITTLE_ENDIAN, and fix the typedefs for
uint32_t, uint16_t and uint8_t appropriately.
BUGS
Currently spottopgm doesn't determine the length of the
input file; this would involve two passes over the input
file. It defaults to 3000 lines instead.
Spottopgm could extract a three-color image (ppm), but I
didn't feel like making the program more complicated than
it is now. Besides, there is no one-to-one correspondence
between red, green, blue and infra-red, visible and ultraviolet.
I've only had a limited number of SPOT images to play
with, and therefore wouldn't guarantee that this will work
on any other images.
AUTHOR
Warren Toomey wkt@csadfa.cs.adfa.oz.au
SEE ALSO
- The rest of the Pbmplus suite.