ENVITiePointSet

This is a reference to an ENVITiePointSet object, which contains a set of tie points used for image-to-image registration. A tie point contains the corresponding x and y pixel coordinates from two images.

Example

This example uses a sample auto-generated tie point file that was created by choosing the default options in the Image Registration workflow, using two input images quickbird_2.4m.dat and ikonos_4.0m.dat. The sample tie point file (SampleTiePoints.pts) and images are available from the ENVI Tutorials web page. Click the Image Registration link to download the .zip file to your machine, then unzip the files. Edit SampleTiePoints.pts to include the full path to the sample images quickbird_2.4m.dat and ikonos_4.0m.dat.

; Start the application

e = ENVI()

; Open two input images

File1 = 'quickbird_2.4m.dat'

Raster1 = e.OpenRaster(File1)

File2 = 'ikonos_4.0m.dat'

Raster2 = e.OpenRaster(File2)

; Open an existing tie point file

tiePointFile = 'SampleTiePoints.pts'

tiePoints = ENVITiePointSet(tiePointFile, $

INPUT_RASTER1=Raster1, INPUT_RASTER2=Raster2)

Syntax

To import an existing set of tie points from an ASCII file:

Result = ENVITiePointSet(Filename)

To start with an empty set of tie points:

Result = ENVITiePointSet(INPUT_RASTER1=raster1, INPUT_RASTER2=raster2)

To create an ENVITiePointSet object from an array of tie points coordinates or structures:

Result = ENVITiePointSet(TIEPOINTS=TiePoints, INPUT_RASTER1=raster1, INPUT_RASTER2=raster2)

Arguments

Filename

Optionally specify an ASCII filename that contains tie points. If you do not specify the Filename argument, an empty ENVITiePointSet object will be created and you must use the Add method to add tie points.

Methods

Properties

Properties marked as (Init) can be set during the initial creation of the object. Properties marked as (Get) can be retrieved. Properties marked as (Set) can be set after initial creation.

INPUT_RASTER1 (Init, Get)

Specify the full path and filename of the first raster.

INPUT_RASTER2 (Init, Get)

Specify the full path and filename of the second raster.

TIEPOINTS (Init)

Specify an array of tie point coordinates with an array size of [4, number of tie points]. Or, specify an array of tie point structures with an array size of [number of tie points].

Specify tie points in the following order: [column of INPUT_RASTER1, row of INPUT_RASTER1, column of INPUT_RASTER2, row of INPUT_RASTER2].

Version History

ENVI 5.2. 1	Introduced
ENVI 5.3.1	Added Dehydrate method
ENVI 5.4	Added Hydrate method

API Version

4.2