Re: Baffled by color postscript

[bowman(at)null.tamu (Kenneth P. Bowman)]

In article <36E43A2C.176B9C7B@cis.rit.edu>, drwpci@cis.rit.edu wrote:

> OK, I've been through many of David's great web pages, and through the portion
> of his book related to the subject. Still, I get only monochrome output, or
> none at all. Here is what I am doing. Note that this works perfectly for the X
> display (that part between the X-only comments). Running on SGI Octane, IDL
> 5.0 MIPS
> 
> ;;;; X-only code starts
> ; loop through the data rgb_index() returns the 24 bit color
> for i = 0, l-1 do begin
>         !p.color = rgb_index(my_rgb[0,i],my_rgb[1,i],my_rgb[2,i])
>         plots, x[i], y[i], psym=4
> end

The IDL PostScript device will display 24-bit color *images*, but will
*not* display 24-bit line graphics (plot, plots, etc.).

I had the same problem a few months back.  Because of the poor
documentation of the PS-device color features, even the RSI support tech
had trouble discovering this.

I filed a request with RSI to add full 24-bit color support to their PS
driver.  I hope you will do the same.  (And anyone else out there who ever
hopes to do 24-bit color graphics!)  I'm disappointed that this has never
been done while scads of other 'useful' features have been added to the
language.

The only workaround I know of is to use a high-resolution 24-bit bitmap
(X-Windows or Z-buffer), write the bitmap to a file, import the bitmap
into a 24-bit-aware program, and then print it.  I've been using
GraphicConverter on my Mac, but something like xv would probably work on
Unix.

Ken Bowman

-- 
Kenneth P. Bowman, Professor                   409-862-4060
Department of Meteorology                      409-862-4466 fax
Texas A&M University                           bowmanATcsrp.tamu.edu
College Station, TX   77843-3150               Change the AT to @