>  Docs Center  >  Libraries  >  Markwardt  >  OPLOTIMAGE

OPLOTIMAGE

OPLOTIMAGE

Name


  OPLOTIMAGE

Author


  Craig B. Markwardt, NASA/GSFC Code 662, Greenbelt, MD 20770
  craigm@lheamail.gsfc.nasa.gov

Purpose


  Overlays an image on an existing plot.

Calling Sequence


  OPLOTIMAGE, img

Description



  OPLOTIMAGE overlays an image on an already-existing set of plot
  axes. It should not matter what plot elements have already be
  displayed, but at least one command is needed to set up the plot
  axes.
  Only the IMGXRANGE and IMGYRANGE keywords, specifying the extent
  of the image, can be given in a call to OPLOTIMAGE.
  See PLOTIMAGE for more detailed information.

Inputs



  IMG - A byte array to be displayed. An image declared as
        ARRAY(M,N) will be M pixels in the x-direction and N pixels
        in the y-direction. The image is resampled via
        interpolation to fill the desired display region.
 

Optional Inputs


  NONE

Input Keyword Parameters



  IMGXRANGE, IMGYRANGE - Each is a two component vector that
                          describes the X and Y position of the first
                          and last pixels.
                          Default: the size of the image in pixels

Outputs


  NONE

Procedure


Example



  This example first constructs an image whose values are found by
      z(x,y) = cos(x) * sin(y)
  and x and y are in the range [-2,2] and [4,8], respectively.
  The image is then plotted in the range [-10, 10] in both x and
  y directions.
 
  x = findgen(20)/5. - 2.
  y = findgen(20)/5. + 4.
  zz = cos(x) # sin(y)
  imgxrange = [min(x), max(x)]
  imgyrange = [min(y), max(y)]
  xr=[-10.,10]
  yr=[-10.,10]
  plotimage, bytscl(zz), imgxrange=imgxrange, imgyrange=imgyrange
  Now for the overlay. A new image is created in the ranges between
  -10 and 0:
      z(x,y) = x y
  x = findgen(20)/2 - 10.
  y = findgen(20)/2 - 10.
  imgxrange = [min(x), max(x)]
  imgyrange = [min(y), max(y)]
  zz = x # y
  oplotimage, bytscl(zz), imgxrange=imgxrange, imgyrange=imgyrange

See Also



  PLOTIMAGE, BYTSCL
  EXTERNAL SUBROUTINES:
  SUBCELL, DEFSUBCELL, TVIMAGE

Modification History


  Written, CM, 1997
  Removed BYTE requirement, added ON_ERROR, CM 19 Apr 2000
  Added copyright notice, CM 25 Mar 2001
  $Id: oplotimage.pro,v 1.2 2001/03/25 18:10:44 craigm Exp $



© 2019 Harris Geospatial Solutions, Inc. |  Legal
My Account    |    Store    |    Contact Us