Name

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      IMAGE_BLEND

Purpose

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      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

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      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

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      Widgets, Object Graphics.

Calling Sequence

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      Image_Blend

Required Inputs

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

Optional Inputs

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      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

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      None.

Side Effects

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      None.

Restrictions

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

Example

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      Image_Blend, Colortable=5

Modification History

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      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.