spottopgm(1L)                                       spottopgm(1L)

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  ultra-
               violet, 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 ultra-
       violet.

       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.

                                                                1