# coyote: IMAGE_BLEND

- coyote/Widget Programming
- coyote/Graphics
- [Source code]

NAME

      IMAGE_BLEND

PURPOSE

      The purpose of this program is to demonstrate how to
      use the alpha channel to blend one image into another.
      The specific purpose is to see a color image on top of
      a gray-scale image, with the gray-scale image showing
      through behind the color image.

AUTHOR

      FANNING SOFTWARE CONSULTING
      David Fanning, Ph.D.
      1645 Sheely Drive
      Fort Collins, CO 80526 USA
      Phone: 970-221-0438
      E-mail: david@idlcoyote.com
      Coyote's Guide to IDL Programming: http://www.idlcoyote.com

CATEGORY

      Widgets, Object Graphics.

CALLING SEQUENCE

      Image_Blend

REQUIRED INPUTS

      None. The images "worldelv.dat" and "ctscan.dat" from the
      examples/data directory are used.

OPTIONAL INPUTS

      backgroundImage::  A 2D image variable that will be used for the background image.
      foregroundImage:   A 2D image variable that will be used for the foreground image.

OPTIONAL KEYWORD PARAMETERS

      COLORTABLE: The number of a color table to use for the foreground image.
      Color table 3 (red temperature) is used as a default.

COMMON BLOCKS

      None.

SIDE EFFECTS

      None.

RESTRICTIONS

      None. The program XCOLORS is required from the Coyote library.

EXAMPLE

      Image_Blend, Colortable=5

MODIFICATION HISTORY

      Written by David Fanning, 30 March 99.
      Fixed bug where I redefined the image parameter. Duh... 1 April 99. DWF.
      Moved the program into the 21st century. :-) 21 March 2003. DWF.
      Added TIFF, GIF (if version supports it), and PS output. 27 December 2006. DWF.