OV-GSO-DC / dustem-wrapper_idl

Blame view

src/idl_misc/coyote_for_Dustemwrap/cgcliptomap.pro 8.35 KB
Edit Raw Normal View History
6db3528a   Jean-Philippe Bernard   adding librairies... 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
 
; docformat = 'rst'
;
; NAME:
;   cgClipToMap
;
; PURPOSE:
;   Allows an image or geoTiff file to be clipped or subset to a map projected boundary.
;
;******************************************************************************************;
;                                                                                          ;
;  Copyright (c) 2012, by Fanning Software Consulting, Inc. All rights reserved.           ;
;                                                                                          ;
;  Redistribution and use in source and binary forms, with or without                      ;
;  modification, are permitted provided that the following conditions are met:             ;
;                                                                                          ;
;      * Redistributions of source code must retain the above copyright                    ;
;        notice, this list of conditions and the following disclaimer.                     ;
;      * Redistributions in binary form must reproduce the above copyright                 ;
;        notice, this list of conditions and the following disclaimer in the               ;
;        documentation and/or other materials provided with the distribution.              ;
;      * Neither the name of Fanning Software Consulting, Inc. nor the names of its        ;
;        contributors may be used to endorse or promote products derived from this         ;
;        software without specific prior written permission.                               ;
;                                                                                          ;
;  THIS SOFTWARE IS PROVIDED BY FANNING SOFTWARE CONSULTING, INC. ''AS IS'' AND ANY        ;
;  EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES    ;
;  OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT     ;
;  SHALL FANNING SOFTWARE CONSULTING, INC. BE LIABLE FOR ANY DIRECT, INDIRECT,             ;
;  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED    ;
;  TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;         ;
;  LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND             ;
;  ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT              ;
;  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS           ;
;  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.                            ;
;******************************************************************************************;
;
;+
; 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.
;
; :Copyright:
;     Copyright (c) 2012, Fanning Software Consulting, Inc.
;-
FUNCTION cgCliptoMap, imageIn, boundary, $
    LATLONBOX=latlonbox, $
    MAP=map, $
    OUTBOUNDARY=outboundary, $
    OUTMAP=outmap, $
    OUTPOSITION=outposition

   Compile_Opt idl2
   
   ; Return to caller if there is an error.
   On_Error, 2
   
   IF N_Elements(imageIn) EQ 0 THEN Message, 'Calling Syntax: clippedImage = cgClipToMap(image, boundary, MAP=map)'
   
   ; Is the imageIn variable a string. If so, it could be the
   ; have of a GeoTiff file for which you can gather the map
   ; projection information.
   IF Size(imageIn, /TNAME) EQ 'STRING' THEN BEGIN
      map = cgGeoMap(imageIn, Image=image, GeoTiff=geotiff, Palette=pal)
   ENDIF ELSE image = imageIn
   
   ; You need a boundary at this point.
   IF N_Elements(boundary) EQ 0 THEN Message, 'A clipping boundary is required.'
   IF N_Elements(boundary) NE 4 THEN Message, 'A clipping boundary must be a four-element array.'
   
   ; You MUST have a map coordinate object at this point.
   IF N_Elements(map) EQ 0 THEN Message, 'A map coordinate object is required.'
   
   ; If the absoulte value of the maximum of the boundary is less that 360, then assume the boundary
   ; is given in lat/lon space and convert it.
   IF Abs(Max(boundary)) LE 360 THEN BEGIN
       xy = map -> Forward(boundary[[0,2]], boundary[[1,3]])
       thisBoundary = [xy[0,0], xy[1,0], xy[0,1], xy[1,1]]
   ENDIF ELSE thisBoundary = boundary
   
   ; Current dimension of the image.
   dims = Image_Dimensions(image, XSIZE=xsize, YSIZE=ysize, TRUEINDEX=trueindex, XINDEX=xindex, YINDEX=yindex)
   IF (trueindex NE -1) && (trueindex NE 2) THEN image = Transpose(image, [xindex, yindex, trueindex])
   
   ; Get the current image range.
   map -> GetProperty, XRange=xr, YRange=yr
   
   ; Create image vectors.
   xvec = cgScaleVector(DIndgen(dims[0]+1), xr[0], xr[1])
   yvec = cgScaleVector(DIndgen(dims[1]+1), yr[0], yr[1])
   
   ; Clip to get new image subscripts.
   xsubs = 0 > Value_Locate(xvec, [thisBoundary[0],thisBoundary[2]]) < (dims[0]-1)
   ysubs = 0 > Value_Locate(yvec, [thisBoundary[1],thisBoundary[3]]) < (dims[1]-1)
   
   ; Output boundary.
   outboundary = [ xvec[xsubs[0]], yvec[ysubs[0]], xvec[xsubs[1]], yvec[ysubs[1]] ]
   outposition = [ xsubs[0], ysubs[0], xsubs[1], ysubs[1] ]

   ; Clip the image.
   IF trueIndex NE -1 THEN BEGIN
      imageType = Size(image, /TYPE)
      subimage = Make_Array(xsubs[1]-xsubs[0], ysubs[1]-ysubs[0], 3, Type=imageType)
      subimage[*,*,0] = image[xsubs[0]:xsubs[1]-1, ysubs[0]:ysubs[1]-1, 0]
      subimage[*,*,1] = image[xsubs[0]:xsubs[1]-1, ysubs[0]:ysubs[1]-1, 1]
      subimage[*,*,2] = image[xsubs[0]:xsubs[1]-1, ysubs[0]:ysubs[1]-1, 2]   
   ENDIF ELSE subimage = image[xsubs[0]:xsubs[1]-1, ysubs[0]:ysubs[1]-1]
   
   ; Create an output map coordinate object.
   map -> GetProperty, MAP_PROJECTION=projection, ELLIPSOID=ellipsoid, ZONE=zone
   mapout = Obj_New('cgmap', projection, Ellipsoid=ellipsoid, ZONE=zone, $
      XRange=[xvec[xsubs[0]],xvec[xsubs[1]]], $
      YRange=[yvec[ysubs[0]],yvec[ysubs[1]]])
   mapOut -> GetProperty, LATLONBOX=latlonBox
   
   RETURN, subimage
   
END