OEPNTTHIN

Description

OEPNTTHIN thins the points in a CATALYST Professional OrthoEngine project file by automatically removing redundant tie points (TP), ground control points (GCP), or both.

Parameters

Name	Type	Length	Value range
InputPRJ: Input OrthoEngine project file *	Text port	1 -
OutputPRJ: Output OrthoEngine project file *	Text port	1 -
Point type	String	1 -	BOTH | GCP | TP Default: BOTH
Number of cells for GCPs	Integer	1 - 1024	3 - 1000 Default: 3
Number of cells for TPs	Integer	1 - 1024	3 - 1000 Default: 5
GCPs per cell	Integer	1 - 1024	1 - 1000 Default: 1
TPs per cell	Integer	1 - 1024	1 - 1000 Default: 2
Thinning options	String	3 -	INACT | DEL Default: INACT
Residual calculation	String	1 -	YES | NO Default: NO
Report	String	0 - 192	See parameter description

* Required parameter

Parameter descriptions

InputPRJ: Input OrthoEngine project file

The name of the input OrthoEngine project file that contains the points to refine.

OutputPRJ: Output OrthoEngine project file

The name of the output OrthoEngine project file.

Point type

The type of points in the OrthoEngine project file to thin.

Number of cells for GCPs

The number of cells into which to divide the input imagery for thinning GCPs. The short-side of the imagery will be divided into the number you specify. The long side will divided automatically into an appropriate number to make square cells. The default value is 3.

Number of cells for TPs

This parameter specifies the number of cells to break the input imagery into for TP thinning. The short-side of the imagery will be broken into the requested number and the long side will automatically be broken into an appropriate number to make square cells. The default value is 5.

GCPs per cell

The number of GCPs to retain after thinning each grid cell. The default value is 1.

TPs per cell

The number of TPs to retain after thinning each grid cell. The default value is 2.

Thinning options

Residual calculation

Whether to calculate residual values during thinning.

Report

Specifies where to direct the generated report.

Available options are:

• LOG: generates a report on the terminal (default)
• <modulename.RPT>: appends a report to the module's RPT file
• DISK: generates a report on file "IMPRPT.LST"

Details

OEPNTTHIN removes redundant TPs and GCPs from an OrthoEngine project.

Automatic TP or GCP collection sometimes provides too many points in each image, and the point distribution may vary. OEPNTTHIN can reduce the number of points while maintaining a more consistent distribution of points across the image. This is achieved by dividing the image into a configurable number of grid cells and selecting points to retain in each grid cell.

OEPNTTHIN reduces the number of points as follows: with each grid cell, the points with the lowest connectivity (smaller number of rays) are removed, leaving the desired number of points in the cell. In this sequence, the points with the best connectivity will remain. If the you select to use residuals for thinning, the residual will also be considered. Points with the lowest connectivity and highest residuals are prioritized for removal.

OEPNTTHIN can be set up to designate the removed points as inactive, or remove them. You can manually examine the points designated inactive in OrthoEngine to decide if they should be removed.

After running OEPNTTHIN, an even distribution of points and proper number of points can be achieved. The model computation time and the error-detection effort should be reduced significantly.