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ENVIRasterSpatialRefPseudo

ENVIRasterSpatialRefPseudo

This routine has been deprecated and renamed to ENVIPseudoRasterSpatialRef.

This is a reference to the ENVIRasterSpatialRefPseudo object.

Pseudo map information refers to a non-standard projection that involves an affine map transformation. When an image is not georeferenced to a standard map projection and you only know the geographic coordinates and map projection of four points in the image, you can define these tie points in an ENVI header file or in the metadata of the raster object. ENVI will use these points to warp the image and to calculate geographic coordinates for each pixel. The pixel size varies in the rectified image. This type of projection contains a high degree of variability and is not geographically accurate; the (x,y) locations in the rectified image are only best guesses.

See ENVI::CreateRasterSpatialRef for details on creating this object. You can also retrieve the reference to an ENVIRasterSpatialRefPseudo object associated with a raster with ENVIRaster's SPATIALREF property. If you print this object, all properties will display regardless of the spatial reference type.

If a data set has more than one type of map information (for example, a standard map projection and pseudo map information), the standard map projection will take precedence and determine the base projection.

Note: To achieve the highest level of accuracy when creating this object, specify values as double-precision floating point numbers.

Example


; Launch the application
e = ENVI()
 
; Define the spatial reference object data
pseudoGeoPoint1 = [1.0000000D, 1.0000000D, -117.07201D, 32.893801D]
pseudoGeoPoint2 = [1002.0000D, 1.0000000D, -116.95856D, 32.873647D]
pseudoGeoPoint3 = [1.0000000D, 1002.0000D, -117.09961D, 32.806283D]
pseudoGeoPoint4 = [1002.0000D, 1002.0000D, -116.98626D, 32.786154D]
 
; Create a custom spatial reference object
spatialRef1 = e.CreateRasterSpatialRef('pseudo', $
  PSEUDO_GEO_POINT_1=pseudoGeoPoint1, $
  PSEUDO_GEO_POINT_2=pseudoGeoPoint2, $
  PSEUDO_GEO_POINT_3=pseudoGeoPoint3, $
  PSEUDO_GEO_POINT_4=pseudoGeoPoint4)
 
; Open a file but override its spatial reference information
file = FILEPATH('qb_boulder_msi', ROOT_DIR=e.ROOT_DIR, $
  SUBDIRECTORY = ['data'])
raster = e.OpenRaster(file, SPATIALREF_OVERRIDE=spatialRef1)
 
; Retrieve and print the spatial reference 
spatialRef = raster.SPATIALREF
PRINT, spatialRef

Methods


None

Properties


Properties marked as (Get) can be retrieved, but not set.

COORD_SYS_CODE (Get)

Use this property to get a geographic (GEOGCS) or projected (PROJCS) coordinate system code.

For a full list of coordinate system strings and codes, refer to the following text files in the \IDLxx\resource\pedata\predefined directory of the ENVI distribution:

  • EnviPEProjcsStrings.txt: PROJCS codes and strings
  • EnviPEGeogcsStrings.txt: GEOGCS codes and strings

COORD_SYS_STR (Get)

Use this property to get a geographic (GEOGCS) or projected (PROJCS) coordinate system string.

For a full list of coordinate system strings and codes, refer to the following text files in the \IDLxx\resource\pedata\predefined directory of the ENVI distribution:

  • EnviPEProjcsStrings.txt: PROJCS codes and strings
  • EnviPEGeogcsStrings.txt: GEOGCS codes and strings

PSEUDO_GEO_POINT_1, PSEUDO_GEO_POINT_2, PSEUDO_GEO_POINT_3, PSEUDO_GEO_POINT_4 (Get)

Each property is a four-element array [X Pixel, Y Pixel, Longitude, Latitude] specifying a geographic corner for a non-georeferenced file. Depending on the data source, not all four properties may contain information.

Version History


ENVI 5

Introduced

ENVI 5.1

Deprecated



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