The Count function method returns the number of tie points in an ENVITiePointSet object.


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 an existing tie point file
tiePointFile = 'SampleTiePoints.pts'
tiePoints = ENVITiePointSet(tiePointFile)
TPCount = tiePoints.Count()
Print, TPCount


Result = ENVITiePointSet.Count([, ERROR=variable])

Return Value

This method returns the number of tie points in an ENVITiePointSet object.




ERROR (optional)

Set this keyword to a named variable that will contain any error message issued during execution of this routine. If no error occurs, the ERROR variable will be set to a null string (''). If an error occurs and the routine is a function, then the function result will be undefined.

When this keyword is not set and an error occurs, ENVI returns to the caller and execution halts. In this case, the error message is contained within !ERROR_STATE and can be caught using IDL's CATCH routine. See IDL Help for more information on !ERROR_STATE and CATCH.

See Manage Errors for more information on error handling in ENVI programming.

Version History

ENVI 5.2. 1


API Version


See Also