Allows an image or geoTiff file to be clipped or subset to a map projected boundary.
Map Utilities
The clipped or subsetted image is returned.
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.
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.
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
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 (c) 2012, Fanning Software Consulting, Inc.