資源共享] IDL開發(fā)專題-IDL下的坐標系及示例
本帖最后由 lianyi_dyq 于 2009-12-23 11:27 編輯
IDL下常用的坐標系有下面三種：
%設備坐標體系（顯示屏幕、打印機紙張）
%規(guī)一化坐標體系
%數(shù)據(jù)坐標體系
無論采用任何的坐標系，顯示對象的坐標都要統(tǒng)一到當前坐標范圍內(nèi)，只有統(tǒng)一了坐標才能正確的顯示數(shù)據(jù)。
下面的例子源碼說明了如何應用這三個坐標系。
 
PRO test_idlcoord
;
oWindow = OBJ_NEW('IDLgrWindow', $
retain =2, $
DIMENSIONS = [800,400])
;顯示體系結(jié)構(gòu)
oView = OBJ_NEW('IDLgrView')
shapeModel = OBJ_NEW('IDLgrModel')
imageModel= OBJ_NEW('IDLgrModel')
oTopModel= OBJ_NEW('IDLgrModel')
oTopModel->add,[imageModel,shapeModel]
oView->add,oTopModel
;讀取數(shù)據(jù)
file = filepath( 'day.jpg', SUBDIRECTORY=['examples','data'] )
READ_JPEG, file,imageData
; Resize the image data
imageData = congrid(imageData,3,360,180)
oImage = OBJ_NEW('IDLgrImage', $
imageData)
imageModel->add,oImage
;讀取矢量文件
shpFilename = filepath( 'shape\continents.shp', SUBDIRECTORY=['resource','maps'] )
shapeFile = OBJ_NEW('IDLffShape', shpFileName)
shapeFile->getproperty, N_Entities = nEntities
FOR i=0, nEntities-1 DO BEGIN
entitie = shapeFile->getentity(i)
IF PTR_VALID(entitie.parts) NE 0 THEN BEGIN
cuts = [*entitie.parts, entitie.n_vertices]
FOR j=0, entitie.n_parts-1 DO BEGIN
tempLon = (*entitie.vertices)[0,cuts[j]:cuts[j+1] - 1]
tempLat = (*entitie.vertices)[1,cuts[j]:cuts[j+1] - 1]
;轉(zhuǎn)換到當前圖像坐標下
tempLon = (REFORM(tempLon) -(-180))
tempLat = (REFORM(tempLat) -(-90))
;
num = N_ELEMENTS(tempLon)
polylines = LINDGEN(num+1)-1
polylines[0] = num
tempPlot = OBJ_NEW('IDLgrPolyline', $
tempLon, $
tempLat, $
Polylines = polyLines , $
Alpha_Channel = 1, $
color = [255,0,0])
shapeModel->add,tempPlot
ENDFOR
ENDIF
shapeFile->destroyentity, entitie
ENDFOR
;
; 圖像坐標顯示
oView->setproperty, viewPlane_Rect = [0,0,800,400]
oWindow->SetProperty, title ='圖像坐標顯示'
oWindow->draw,oView
;停頓兩秒
wait,2
;歸一化坐標顯示
;銷毀原來的
OBJ_DESTROY,oTopModel
;建立新的
shapeModel = OBJ_NEW('IDLgrModel')
imageModel= OBJ_NEW('IDLgrModel')
oTopModel= OBJ_NEW('IDLgrModel')
oTopModel->add,[imageModel,shapeModel]
oView->add,oTopModel
;
oImage = OBJ_NEW('IDLgrImage', $
imageData)
imageModel->add,oImage
;獲取當前圖像對象的X、Y方向的范圍
oImage->getproperty, xRange = xRange,yRange = yRange
;求出歸一化系數(shù)
xr = norm_coord(xRange)
;解析：xrange =[0,360],xr是兩個參數(shù),[-0.00000000 ,0.0027777778],通過設置該參數(shù)，
;那么轉(zhuǎn)換后x方向的原數(shù)據(jù)坐標為xr[0]+xr[1]*xrange[0]= -0+0.002777*0 = 0
; xr[0]+xr[1]*xRange[1]= -0+0.002777*360 =1
; 可測試 Norm_Coord([-100,100]) = [0.500000 , 0.00500000]
;
yr = norm_coord(yRange)
oImage->setproperty, xCoord_conv = xr, $
yCoord_conv = yr
;
shapeFile = OBJ_NEW('IDLffShape', shpFileName)
shapeFile->getproperty, N_Entities = nEntities
FOR i=0, nEntities-1 DO BEGIN
entitie = shapeFile->getentity(i)
IF PTR_VALID(entitie.parts) NE 0 THEN BEGIN
cuts = [*entitie.parts, entitie.n_vertices]
FOR j=0, entitie.n_parts-1 DO BEGIN
tempLon = (*entitie.vertices)[0,cuts:cuts[i+1] - 1]
tempLat = (*entitie.vertices)[1,cuts[j]:cuts[j+1] - 1]
;
;轉(zhuǎn)換到歸一化的坐標系下顯示
tempLon = FLOAT((REFORM(tempLon) -(-180))) /360.
tempLat = FLOAT((REFORM(tempLat) -(-90)))/180.
;
num = N_ELEMENTS(tempLon)
polylines = LINDGEN(num+1)-1
polylines[0] = num
tempPlot = OBJ_NEW('IDLgrPolyline', $
tempLon, $
tempLat, $
Polylines = polyLines , $
Alpha_Channel = 1, $
color = [255,0,0])
shapeModel->add,tempPlot
ENDFOR
ENDIF
shapeFile->destroyentity, entitie
ENDFOR
;
; 設置顯示區(qū)域坐標
oView->setproperty, viewPlane_Rect = [0,0,1,1]
oWindow->SetProperty, title ='歸一化坐標顯示'
oWindow->draw,oView
;停頓兩秒
wait,2
;地理坐標顯示
;銷毀原來的
OBJ_DESTROY,oTopModel
;建立新的
sMap = map_proj_init('Interrupted Goode')
; 或用下面的投影
; ;全球的“等距圓柱投影”
; sMap = Map_Proj_Init('Equirectangular' , $
; Limit = [-90,-180,90,180] , $
; Center_Longitude = 0 )
shapeModel = OBJ_NEW('IDLgrModel')
imageModel= OBJ_NEW('IDLgrModel')
oTopModel= OBJ_NEW('IDLgrModel')
oTopModel->add,[imageModel,shapeModel]
oView->add,oTopModel
;
;對圖像進行糾正
;
red= REFORM(imageData[0,*,*])
green= REFORM(imageData[1,*,*])
blue= REFORM(imageData[2,*,*])
red1 = map_proj_image( red, MAP_STRUCTURE=sMap, MASK=mask, $
UVRANGE=uvrange, XINDEX=xindex, YINDEX=yindex )
green1 = map_proj_image( green, XINDEX=xindex, YINDEX=yindex )
blue1 = map_proj_image( blue, XINDEX=xindex, YINDEX=yindex )
imageData = BYTARR(4,360,180)
imageData[0,*,*] = red1
imageData[1,*,*] = green
imageData[2,*,*] = blue
;設置掩膜
imageData[3,*,*] = mask*255b
;
uRange = uvRange[2]-uvRange[0]
vRange = uvRange[3]-uvRange[1]
oImage = OBJ_NEW('IDLgrImage', $
imageData, $
BLEND_FUNCTION = [3, 4], $
dimensions=[uRange,vRange], $ ;維數(shù)--大地坐標
location=uvRange[0:1] ) ;位置--大地坐標
imageModel->add,oImage
; ;
shapeFile = OBJ_NEW('IDLffShape', shpFileName)
shapeFile->getproperty, N_Entities = nEntities
FOR i=0, nEntities-1 DO BEGIN
entitie = shapeFile->getentity(i)
IF PTR_VALID(entitie.parts) NE 0 THEN BEGIN
cuts = [*entitie.parts, entitie.n_vertices]
FOR j=0, entitie.n_parts-1 DO BEGIN
tempLon = (*entitie.vertices)[0,cuts[j]:cuts[j+1] - 1]
tempLat = (*entitie.vertices)[1,cuts[j]:cuts[j+1] - 1]
;
;轉(zhuǎn)換到m制坐標系下顯示
vert = MAP_PROJ_FORWARD([tempLon,tempLat], $
Map_Structure = sMap, $
Polylines = polyLines)
;
tempPlot = OBJ_NEW('IDLgrPolyline', $
vert[0,*], $
vert[1,*], $
Polylines = polyLines , $
Alpha_Channel = 1, $
color = [255,0,0])
shapeModel->add,tempPlot
ENDFOR
ENDIF
shapeFile->destroyentity, entitie
ENDFOR
;
; 設置顯示區(qū)域坐標
oView->setproperty, viewPlane_Rect = [uvrange[0],uvrange[1],uRange,vRange]
oWindow->SetProperty, title ='Interrupted Goode 投影下m制坐標顯示'
oWindow->draw,oView
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