Adding colour

While reading the section on the image command you may have wondered why the command to choose grey levels is called `colour'. Because it can be used to load an existing colour lookup table. This can be done before or after `image'. To put some colour into the display we already have:

   ICL> colour contour_lut

There are a number of prepared colour lookup tables. They are `.sdf' files, similar to other data files. By convention their names end in `_lut.sdf', and they are stored in a directory pointed to by the Unix shell environment variable `FIGARO_PROG_S'. To see a list of colour tables in that directory:

   % ls $FIGARO_PROG_S/*_lut.sdf

Finally, how do you prevent line graphics from resetting your image display? You will recall that the line graphics device is selected with `soft', while the imaging device is selected with `idev'. You can simply choose separate windows. Consider this:

   % xmake xwindows -c 16
   % xmake xwindows2 -c 128
   ICL> soft xw
   ICL> idev x2w

This will separate the output into two windows. There are four windows possible, but notice the different names in `xmake' and `soft'/`idev'. The `-c' options also reduce the line graphics window to the 16 colours reserved for this, and increase the imaging window to 128 colours.