when use RGB and when use RGBA?

• To: "visad-list@xxxxxxxxxxxxx" <visad-list@xxxxxxxxxxxxx>
• Subject: when use RGB and when use RGBA?
• From: Helen Yi <y.yi@xxxxxxxxxxxxx>
• Date: Wed, 04 Sep 2002 11:57:05 -0400

Hi

I need some help on how to determine  when and where use RGB  and RGBA.

Suppose  the normal range of a flat field is between 0 and 100, but some
points are with negative values.
How can I make a color display but use grey color represent  the
negative values?


Thanks for your help.

helen

• Follow-Ups:
  • Re: when use RGB and when use RGBA?
    • From: Bill Hibbard