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  >  Docs Center  >  ENVI API  >  Processing  >  ENVIFilterTiePointsByFundamentalMatrixTask

ENVIFilterTiePointsByFundamentalMatrixTask

ENVIFilterTiePointsByFundamentalMatrixTask

This task uses the fundamental matrix to constrain the location of the tie points.

The following diagram shows where this task belongs within an image-to-image registration workflow:

References

Jin, Xiaoying. ENVI automated image registration solutions. Harris Geospatial Systems whitepaper (2017). Available online at http://www.harrisgeospatial.com/Portals/0/pdfs/ENVI_Image_Registration_Whitepaper.pdf.

Jin, Xiaoying, and Robert Schafer. Method and system for automatic registration of images. Exelis, Inc., assignee; now owned by Harris Corporation. U.S. Patent No. 9,245,201 (issued January 26, 2016).

Example


This example uses sample images from the Image Registration tutorial. The files are available on the ENVI Resource DVD under the /image_reg directory or from the ENVI Tutorials web page. Click the "ENVI Tutorial Data" hyperlink. Copy the files to your local drive.

; Start the application
e = ENVI()
 
; Open input rasters
File1 = 'quickbird_2.4m.dat'
File2 = 'ikonos_4.0m.dat'
Raster1 = e.OpenRaster(File1)
Raster2 = e.OpenRaster(File2)
 
; Get the auto tie point generation task from the catalog of ENVITasks
Task = ENVITask('GenerateTiePointsByCrossCorrelation')
 
; Define inputs
Task.INPUT_RASTER1 = Raster1
Task.INPUT_RASTER2 = Raster2
 
; Run the task
Task.Execute
 
; Get the output tie points
TiePoints = Task.OUTPUT_TIEPOINTS
 
; Get the tie point filter task from the catalog of ENVITasks
FilterTask = ENVITask('FilterTiePointsByFundamentalMatrix')
 
; Define inputs
FilterTask.INPUT_TIEPOINTS = TiePoints
 
; Run the task
FilterTask.Execute
 
; Get the output tie points
TiePoints2 = FilterTask.OUTPUT_TIEPOINTS
 
; Get the image-to-image registration task from the catalog of ENVITasks
RegistrationTask = ENVITask('ImageToImageRegistration')
 
; Define inputs
RegistrationTask.INPUT_TIEPOINTS = TiePoints2
RegistrationTask.WARPING = 'Triangulation'
 
; Run the task
RegistrationTask.Execute
 
; Get the output raster
WarpedRaster = RegistrationTask.OUTPUT_RASTER
 
; Get the collection of data objects currently available in the Data Manager
DataColl = e.Data
 
; Add the output to the Data Manager
DataColl.Add, WarpedRaster
 
; Display the input rasters
View1 = e.GetView()
Layer1 = View1.CreateLayer(Raster1)
Layer2 = View1.CreateLayer(Raster2)
 
; Display the result
Layer3 = View1.CreateLayer(WarpedRaster)

Syntax


Result = ENVITask('FilterTiePointsByFundamentalMatrix')

Input properties (Set, Get): INPUT_TIEPOINTS, OUTPUT_TIEPOINTS_URI, REPROJECTION_ERROR_THRESHOLD

Output properties (Get only): OUTPUT_TIEPOINTS

Properties marked as "Set" are those that you can set to specific values. You can also retrieve their current values any time. Properties marked as "Get" are those whose values you can retrieve but not set.

Methods


This task inherits the following methods from ENVITask:

AddParameter

Execute

Parameter

ParameterNames

RemoveParameter

Properties


This task inherits the following properties from ENVITask:

COMMUTE_ON_DOWNSAMPLE

COMMUTE_ON_SUBSET

DESCRIPTION

DISPLAY_NAME

NAME

REVISION

TAGS

This task also contains the following properties:

BASE_RASTER (optional)

Set this property to one of the following strings, indicating which input raster is the base raster:

  • Raster 1 from Tie Points (default)
  • Raster 2 from Tie Points

INPUT_TIEPOINTS (optional)

This is a reference to the ENVITiePointSet object generated from ENVIGenerateTiePointsByCrossCorrelationTask or ENVIGenerateTiePointsByMutualInformationTask.

OUTPUT_TIEPOINTS

This is a reference to an ENVITiePointSet object with the output tie points.

OUTPUT_TIEPOINTS_URI (optional)

Specify a string with the fully qualified path and filename for OUTPUT_TIEPOINTS.

REPROJECTION_ERROR_THRESHOLD (optional)

Specify the reprojection error threshold to use. It is defined as the perpendicular distance (in pixel units) of a point in one image from its corresponding epipolar line computed from a point in another image. The default value is 10.0.

Version History


ENVI 5.2, Service Pack 1

Introduced

API Version


3.2

See Also


ENVITask, ENVITask::Parameter, ENVIFilterTiePointsByGlobalTransformTask, ENVIFilterTiePointsByPushbroomModelTask, ENVIGenerateTiePointsByCrossCorrelationTask, ENVIGenerateTiePointsByMutualInformationTask, ENVIImageToImageRegistrationTask, ENVITiePointSet



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