# coyote: CGIMAGEINFO

- coyote/Graphics
- [Source code]

Description

      The purpose of this program is allow interactive inquiry of image
      position and values for images displayed with cgImage.
      After a call to cgImage, cgImageInfo can be called and the user
      can use the cursor to click in the image display window. If the user clicks
      inside the image, the image location and value will be printed out in the
      user's IDL console window. The cgImageInfo program blocks the IDL command
      line until the RIGHT mouse button is clicked in the image display window.
      This cgImageInfo program is designed to work for the last image displayed with cgImage
      on a Windows or X device. Precautions are taken to help you avoid shooting
      yourself in the foot, but I can't anticipate every action a user might take at the
      IDL command line. Pay particular attention to exiting the program with the RIGHT mouse
      button before you close or kill the current graphics window. Failure to do so will
      put you into a very strange and precarious state from which no rescue is possible.
      You might want to consider using the Catalyst Program `IMGWIN <http://www.idlcoyote.com/catalyst/imgwin.html>`
       as an alternative to cgImageInfo.

Categories

      Graphics

Params

      image: in, required,
           A 2D or 3D image array. Values will be returned from this image.
           In versions of IDL < 8.0, it is possible to use a HASH object of
           keys/images where this program will describe the value for each of
           the images in the HASH object.
      position: in, optional, type=float
           A four-element floating array giving the position of the image in
           the display window. If not provided, the image position will be
           retrieved from the last image position used with cgImage.

Examples

      To display an image with axes and then inquire about it::
          filename = FILEPATH(SUBDIR=['examples','data'], 'worldelv.dat')
          image = BYTARR(360,360)
          OPENR, lun, filename, /GET_LUN
          READU, lun, image
          FREE_LUN, lun
          thisPosition = [0.1, 0.1, 0.9, 0.9]
          cgImage, image, /KEEP_ASPECT,  POSITION=thisPosition, /AXES
          cgImageInfo, image

Author

      FANNING SOFTWARE CONSULTING::
          David W. Fanning
          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

History

      Change History::
       Written by: David W Fanning, 16 March 2008.
       Added ability to specify position directly in call. 20 March 2008. DWF
       Changed cursor operation to conform with expected differences
          between Windows and UNIX. 20 March 2008, DWF.
       Slightly modified screen directions. 16 November 2010. DWF.
       Modified so that multiple images/grids can be described 18 May 2011. MHS

Copyright

      Copyright (c) 2008-2011, Fanning Software Consulting, Inc.