Tie-Point Collection and Refinement Aerial module

Name	Caption
Input Scenes	Input scene folder
Output Folder	Output folder
Send Email	Email notification settings
Overwrite Results	Overwrite existing results
Save Intermediate Files	Save intermediate files
Subsets	The number of subsets to use during TP collection
Matching Channels	Matching channels
Collect TPs Using FBM	Whether to collect TPs using FBM or not
Overview Level	The overview level to use during FBM
Distribution Area	Area of image in which to distrbute TPs
Number of Key Points Per Image	Number of key points to collect during FBM.
Photo Feature Mask	Apply a local mask to define the area over which valid features are found
Margin Distance	The distance to expand the Photo Feature Mask
Thin TPs During FBM	Whether to thin TPs during FBM or not
Cells Per Image	Define the grid cells per image during FBM thinning
Perform Camera Self-Calibration	Whether to perform self-calibration or not
Number of Images To Use During Self-Calibration	Number of Images To Use During Self-Calibration
Collect TPs Using FFTPB	Whether to collect TPs using FFTPB or not
Retain FBM TPs	Whether to keep tie points from the FBM pass
Number of TPs Per Image	Number of TPs to collect during FFTPB.
TP Search Radius	Tie point search radius
TP Minimum Score	Tie point minimum score
Refine Tie Points	Whether to refine tie points
Rejection Method	TP rejection method
TP Residual Target	TP residual target
Deactivate Images Below TP Threshold	Whether to deactivate images with less than a certain amount of TPs or not
Minimum Number of TPs	The number of TPs an image must have to be left active
Rejection Action	Remove or deactivate TPs rejected during thinning and refinement

Parameter descriptions

Input Scenes

The path and name of a folder containing a valid CATALYST Professional OrthoEngine project file (oe.prj) or valid GDB-supported images.

This parameter can be specified by using any of the following:

Path and name of a folder of input images; for example, C:\data
Path and name of a folder containing an OrthoEngine project file; for example, C:\data\data-ingest_RAW_PAN.prj
Path and name of a folder with a wildcard to filter the imagery by file name or type; for example, C:\data\*_PAN.pix
Path and name of a folder path with a wildcard to filter by OrthoEngine project file; for example, C:\data\*_PAN.prj
You can also specify an MFILE as input. An MFILE is a text file with an .mfile file name extension. For more information on this type of file, see About the MFILE format.

Output Folder

The path and name of the folder to which to write the output files.

Send Email

If necessary, you can set up CATALYST Enterprise to send an email notification on job start and job completion.

With this check box selected, an email message is sent to each address specified in the Email Addresses box after the job starts and on completion.

You can specify one or more addresses, and each must be separated by a comma or a semi-colon. The email address of the user currently logged in displays by default.

Overwrite Results

Select this check box to overwrite the existing output files, if any exist. If this check box is left clear, and an output file exists in the relevant folder, the status of the job displays a message informing you of the existence and name of the output file. The message is also written to the event log of the job.

Save Intermediate Files

Select this check box to save any supporting files created during processing.

By keeping the files, you can use them to analyze intermediate results and, if necessary, fix any minor issues. You can then restart the job without having to regenerate all the supporting data, thereby reducing processing time.

Note: Intermediate files can consume a large quantity of disk space, thus it is a good idea to delete them when they are no longer needed.

Subsets

With large volumes of data, it is more efficient to run the TP collection jobs using subsets.

For example, a value of 4 will split the input scenes into four groups and collect TPs in parallel.

Matching Channels

The channel or channels in the image file from which to extract the TPs.

When this parameter specifies multiple channels, the channel data is averaged together. If no value is specified for this parameter, its value defaults to channel 1.

Collect TPs Using FBM

If selected, TPs will be collected using FBM.

Overview Level

The overview level to use during FBM.

Note: Decreasing the overview level will increase processing time. Using overview level 8 will usually produce good results, but for smaller images you may need to decrease the overview level used. If FBM does not find many points, lower this value.

Distribution Area

The area of each image in which to distribute tie points (TP).

You can select from the following:

Entire: For use typically with aerial imagery, evenly distributes TPs in the entire image being matched. The number of samples is multiplied by the overlap percentage and the density of candidate distribution is relatively constant.
Overlap: For use typically with satellite imagery in which the overlapping areas may be less regular than aerial imagery, evenly distributes TPs only in the area that overlaps the adjacent image. Smaller overlaps provide a distribution of candidates that is more dense.

Number of Key Points Per Image

The target number of key points to collect per image.

Note: The actual number of extracted key points may differ due to a lack of features in the image or because of the minimum numbers of key points enforced to improve the distribution, match-ability, or both.

Photo Feature Mask

A local mask used to define the area over which valid features are found.

To exclude pixels near the fiducial marks (scanned-film airphotos), select Fiducial, and then in the Margin Distance box, type or select the amount to expand the mask from the fiducial locations.
To exclude pixels along the edge of each image, select Edge, and then in the Margin Distance box, type or select the amount to expand the mask from the image edges.

Margin Distance

The distance to expand the Photo Feature Mask.

Thin TPs During FBM

If selected, TPs will be thinned during FBM based on the value entered for Cells Per Image.

Cells Per Image

If Thin TPs During FBM is selected, this value will control the number of grid cells used during FBM thinning.

That is, by defining the number of grid cells per image, you can control the amount of thinning that occurs. The greater the value, the greater the number of points retained. The thinning process divides each image into the number of grid cells you specify and keeps the TPs with the most connectivity in each grid cell.

Perform Camera Self-Calibration

If selected, attempts to remove unmodeled lens distortion using FBM TPs.

Note: Camera self-calibration is required when no external camera calibration has been provided, or if the provided external camera calibration is not accurate.

Note: This parameter is experimental.

Number of Images To Use During Self-Calibration

If Perform Camera Self-Calibration is selected, this parameter controls the number of photos used during self-calibration.

Using 50 to 100 photos tends to produce the best results, and will run faster for large projects.

Collect TPs Using FFTPB

If selected, TPs will be collected using FFTPB.

Retain FBM TPs

If selected, FBM TPs will be retained before running FFTPB.

Note: The models created using the FBM TPs are respected even if the FBM TPs are removed.

Number of TPs Per Image

The target number of TPs to collect per image during FFTPB.

TP Search Radius

The maximum search radius, in pixels, for TPs. This controls the size of the area to search when seeking a match. A higher value increases the search area to be considered while matching each point, thereby increasing the processing time. Pixels in the search area is inspected for similarity within a small window (template) from the raw image. The pixel with the highest degree of similarity is accepted if it passes the match-acceptance criteria. The specified value should be slightly greater than the expected inaccuracy of registration between the two images, due to all possible causes. For example, if the nominal model of a satellite image is known to be accurate to approximately 100 pixels, and DEM inaccuracies can add another 30 pixels, then the search radius should be set to about 150 pixels. The poorer the accuracy of the initial match location estimate, the larger the search radius should be.

TP Minimum Score

The minimum-acceptance value for the correlation score that is considered to be a valid match. Valid values range from 0 to 1. For a match to become a TP, its match score must be greater than the specified value.

Refine Tie Points

Select this check box to refine the tie points collected. If this check box is left clear, you must verify and, if necessary, manually refine the tie points.

Rejection Method

The method used to reject TPs.

Available options are:

Progressive:Residuals greater than 1,000, 500, 100, 20, and 10 pixels are removed iteratively before applying the TP Residual Target
Direct:Residuals greater than the value specified by TP Residual Target are removed immediately

TP Residual Target

The job removes TPs until the TP Residual Target is reached. The method in which TPs are removed is defined by the Rejection Method.

Deactivate Images Below TP Threshold

If selected, deactivates images with less than Minimum Number of TPs as they are likely bad images and can have negative effects on DEM Extraction and Mosaicking.

Minimum Number of TPs

If Deactivate Images Below TP Threshold is selected, specifies the number of TPs an image must have to remain active.

Rejection Action

Select whether to remove or deactivate tie points (TP) rejected during thinning and refinement.

The available options are as follows:

Deactivate: renders rejected points inactive. Inactive points are excluded from the math-model calculation.
Delete: removes rejected points.

Details

General job details

Preprocessing requirements

Before running this module, the following requirements must be met to ensure the job processes successfully and produces accurate results:

Input aerial scenes: the folder specified for tie-point collection must contain a valid CATALYST Professional OrthoEngine project file. A valid project file contains all the aerial scenes, exterior orientation (EO), camera model, and map units. The input scenes can be the output folder of the Airphoto Ingest for AT module when it contains an OrthoEngine project file. Alternatively, the input scenes can be the output folder of the GCP Collection module.

Module details

The Tie-Point Collection and Refinement Aerial module reads the Input Scenes folder for valid imagery files or a valid OrthoEngine project file (oe.prj).

When all of the TP-collection jobs are complete, the collected TPs are refined to meet the specified accuracy requirements, and a report summarizing the accuracy is created. A final OrthoEngine project file is created with the refined points and updated math model.

Job results

The Tie-Point Collection and Refinement Aerial module collects and refines the TPs of all input scenes.

The module creates a CATALYST Professional OrthoEngine project file (oe.prj) for each scene type containing of all the refined and collected TPs and the refined math model. In addition, the Tie-Point Collection and Refinement Aerial module creates a series of summary files in text format.

The Tie-Point Collection and Refinement Aerial module produces the following output:

Final CATALYST Professional OrthoEngine project file of the collected and refined TPs.
Summary report, in text format, containing details of the processing.
Summary report, in text format, of the resulting accuracies of the images after TP collection and refinement.
A folder, intermediates, which contains files of intermediate results. You can use these files to rerun the job, if necessary. After completing quality assurance (QA), you can remove this folder.

You can now open the scenes in CATALYST Professional Focus or open the OrthoEngine project file in OrthoEngine to perform QA, or proceed to use the next module in the CATALYST Enterprise workflow. Typically, this is to use one or both of the following:

DEM Extraction module
Orthorectification module

Tie-Point Collection and Refinement Aerial module

Description

Parameters

Parameter descriptions

Details