# coyote: CGCLIPTOMAP

- coyote/Map Utilities
- [Source code]

Description

      Allows an image or geoTiff file to be clipped or subset to a map projected boundary.

Categories

      Map Utilities

Returns

      The clipped or subsetted image is returned.

Params

      imageIn: in, required, type=varies
          Either a 2D or true-color image (in which, in both cases, a map coordinate object must be provided with the
          MAP keyword) or the name of the GeoTiff file from which an image and a map coordinate object
          can be obtained.
      boundary: in, required, type=fltarr
          A four-element array containing the map boundary to which the image should be clipped.

Keywords

      latlonbox: out, optional, type=fltarr
          A four-element array representing the boundary of the output image in
          the Google Map preferred form of [north, south, east, west] in decimal
          degrees.
      map: in, required, type=object
          A map coordinate object (cgMap) that maps or georeferences the input image.
      outboundary: out, optional, type=fltarr
          A four-element array containing the final map boundary of the clipped image.
          The boundary will be in XY coordinates (projected meters).
      outmap: out, optional, type=object
          An output map coordinate object (cgMap) that describes the output image.
      outposition: out, optional, type=intarr
          A four-element array containing the pixel locations of the output image
          in the input image pixel coordinate system: [x0,y0,x1,y1]. In other words,
          these are the values used to subset the input 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, 16 August 2012. DWF.
         If the absolute value of the maximum of the boundary is LE 360, assume you need to convert
            from lat/lon space to projected meter space. 23 Aug 2012. DWF.
         Added MAPOUT and LATLONBOX keywords. 1 Nov 2012. DWF.
         Added OUTPOSITION keywords. 29 Nov 2012. DWF.
         I have reason to believe the way I was creating the location vectors and
            and image subset in this program was causing me to be 1 pixel off in
            creating the image subset. The algorithm has been tweaked to correct this. 12 Dec 2012. DWF.
         Duh! Changed the name of MapOut keyword to OutMap to make it work, but forgot to change
             the variable name. Output map coordinate object now returning properly. 20 May 2014. DWF.

Copyright

      Copyright (c) 2012, Fanning Software Consulting, Inc.