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| Name | Caption |
|---|---|
| Input Scenes | Input file, folder, or text file |
| Output Folder | Output folder |
| Ingest Method | Link or import data |
| Output File Type | Output file type |
| Output File Options | Output file options |
| Overwrite Results | Overwrite existing results |
| Send Email | Email notification settings |
| Product Type | Type of product to mosaic |
| Math Model Filter | Input math model filter |
| RF Math Model Order | RPC adjustment order |
| Source Background Type | Source background type |
| Source Background Value | Source background pixel value |
| Output Background Value | Output background value |
| DEM Source | DEM tile source |
| Master Matching Channel | Master matching channel |
| Reference Images | Input reference images folder |
| Reference Channel for Matching | Reference image channel to use for matching |
| Sampling Method | GCP sampling method |
| GCP Samples | Number of GCP samples to collect |
| Matching Algorithm | Matching algorithm |
| Collection Strategy | Number of passes for GCP collection |
| Search Radius | Search radius (pixels) |
| Minimum Score | Minimum score (percentage) |
| Chip Database File | Input chip database file |
| Chip Channels | Input chip database channels |
| Chip Matching Algorithm | Chip Matching algorithm |
| Chip Search Radius | Chip Search radius (pixels) |
| Chip Minimum Score | Chip minimum score (percentage) |
| Road Network | Input road network path |
| Road Width Field Name | Input road width field name |
| Road Width Scale & Offset | Input road width scale & offset |
| Polygon Vector File | Input polygon vector file |
| GCP Text Files | Input GCP text file or files |
| GCP Text File Format | File format of GCP text file |
| Water Mask File | Input water-mask file |
| Refine GCPs | Whether to refine GCPs |
| Rejection Method | GCP rejection method |
| Rejection Method Thresholds | GCP rejection method thresholds |
| Maximum GCPs | Maximum GCPs to accept |
| Minimum GCPs | Minimum GCPs to accept |
| Collect Tie Points | Collect tie points |
| Sampling Method | Tie-point-sampling method |
| TP Samples | Number of tie point samples to collect |
| Trials per TP | Number of attempts to collect a TP for each candidate |
| Distribution Area | Area of image in which to distrbute TPs |
| Matching Algorithm | Matching algorithm |
| Matching Channels | Matching channels |
| TP Search Radius | Tie point search radius |
| TP Minimum Score | Tie point minimum score |
| TP Rejection Method | Tie point rejection method |
| TP Rejection Method Thresholds | Tie point rejection method thresholds |
| Pansharpen Order | Pansharpening order |
| Pansharpening Method | Pansharpening method to use |
| Multispectral Sharpening Channels | Multispectral sharpening channels |
| Multispectral Reference Channels | Multispectral reference channels |
| Resampling Method | Resampling method |
| Enhance | Whether to enhance UNB pansharpened images |
| Edge Sharpen | Amount of sharpening to image edges |
| AdaptRadiometry | Adapt radiometric values to input MS images |
| Output Map Units | Output projection |
| Panchromatic Pixel Output Size | Panchromatic output pixel size |
| Multispectral Pixel Output Size | Multispectral output pixel size |
| Resampling Method | Resampling method |
| Resampling Method Extra Options | Extra options for resampling method |
| Sorting Method | Image sorting method |
| Starting Image | Starting image |
| Normalization Method | Normalization method |
| Normalization Method Extra Options | Normalization options |
| Color Balancing Method | Color-balancing method |
| Color Balancing Extra Options | Color-balancing options |
| Global Color Balance Mask File | Global color-balancing mask file |
| Global Color Balance Mask Layer | Global color-balancing mask layer |
| Global Color Balance Mask Segment | Global color-balancing mask segment |
| Cutline Method | Cutline method |
| Cutline Method Extra Options | Cutline options |
| Auto Constrain | Constrain cutlines to image centers |
| Factor | Auto Constrain Factor value |
| Simplify Cutlines | Simplify generated cutlines |
| Simplification Level | Level of simplification |
| Global Cutline Avoidance Mask File | Global cutline-avoidance mask file |
| Global Cutline Avoidance Mask Layer | Global cutline-avoidance mask |
| Global Cutline Avoidance Mask Segment | Global cutline-avoidance mask segment |
| Area of Interest File | Area-of-interest vector file |
| Crop Tiles to AOI | Crop tiles to area of interest |
| Tile Base Name | Base name |
| Tile Specification | Mosaic tile specification |
| Height | Height of the mosaic tile, in pixels |
| Width | Width of the mosaic tile, in pixels |
| Vertical Overlap | Vertical overlap between tiles |
| Horizontal Overlap | Horizontal overlap between tiles |
| Tile File | File containing tile-definition layer |
| Segment Number | Vector segment in tile file |
| Field Name | File containing tile-definition layer |
| Coordinate Type | Type of coordinates in script |
| Tile Position Transformation | Defines grid to align mosaic tiles |
| Blend Width | Cutline blend width |
| Create Source Map | Create source map |
| Existing Tile Rule | Rule for processing existing tile |
| Delete Empty Tiles | Whether to delete empty tiles |
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Input Scenes
The path and name of the folder containing the raw images to process.
Output Folder
The path and name of the folder to which to write the output files.
If tiled output is specified, tiles are processed by the processing nodes configured by the CATALYST Enterprise, and are stored in the specified output folder. Local copies of the tiles on processing nodes are automatically deleted. The output tile file names are generated automatically according to the Tile Base Name.
Ingest Method
Select whether to link or import the data specified in the scene folder.
This method may take longer to ingest the data; however, it improves the overall performance of the workflow.
This method ingests data very quickly; however, subsequent steps of the workflow may take longer to complete.
Output File Type
The format of the output file.
For more information on the supported file formats, see GDB-supported file formats.
Output File Options
The options to apply when creating the output file or files. The available options are specific to the file format; in each case, the default of no options is allowed.
For more information on the options available for the output file type you specify, see GDB-supported file formats.
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.
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.
Product Type
From the list, select the type of product you want to mosaic.
This parameter is optional.
Math Model Filter
The math model to use for collection of ground control points (GCPs) and, subsequently, orthorectification.
The module first attempts to use the selected math model. If required information is missing from the user-defined math model, the module automatically tries to use another math-model option, and displays a warning message.
RF Math Model Order
When using the Rational Function with satellite imagery, you can modify the RF math model to better agree with collected ground control points (GCPs) by selecting the correct RF math-model order.
Typically, performing a first-order transformation is best, except when the GCPs are not well distributed. If your GCPs are clustered together, a first-order transformation may introduce new and significant errors in the image away from the GCPs. If your GCPs are not well distributed, you will probably obtain better results with the zero-order transformation.
Source Background Type
The method to use to determine which pixels in the source image to process as background (NoData) pixels. In general, if a pixel is considered NoData, the module processes it in a specific manner.
If the Any option or the All option is selected, a value must be specified for the Source Background Value parameter.
File Metadata, else None: reads the NoData value from the input-file metadata. The module first checks for the file-level metadata tag NO_DATA_VALUE in the source raster. If the tag is present, this value is used as a default for all channels in the file. Next, the module checks for channel-level NoData tags; if one is found, the channel-level value overrides the file-level value for that channel.
If there are channel-level NoData tags, but no file-level tag, a pixel is considered as NoData if each of the channels with a NoData tag corresponds to its NoData value. In this case, channels without a NoData tag are ignored when identifying background pixels.
If the file does not contain NoData tags, all pixels in the source image are considered valid.
For specific examples, see the Source Background Value parameter description.
Source Background Value
The source background value is provided as either a single number (applied to all channels) or as a pixel "stack" (a comma-delimited list of values). If a pixel stack is provided, but the number of values does not equal the number of channels, the list is truncated or the last value is repeated as necessary. The background values provided is truncated to the range allowed by the source image data type.
Source Background Type set to All and Source Background Value set to 0: a pixel is considered background if all three channels are zero.
Output Background Value
The background (NoData) value to use for pixels that are not populated.
The specified background value is truncated to the range allowed by the source image data type.
When you specify one value, all channels are set to the same NoData value. If you want to specify different values for various channels, separate the values with commas. For example, to specify -32768 for channel 1 and zero for channel 2 (and any subsequent channels), enter "-32768, 0".
DEM Source
The name of a single digital elevation model (DEM) file or a folder containing one or more DEM tiles.
The index.txt file lists the DEM files contained in the specified folder and provides information describing each DEM tile. The information in the DEM index file supersedes other DEM parameters in the module; all other DEM-related parameters are ignored. For more information about the format of the index.txt file and specific requirements for the individual DEM tiles, see Format of the DEM index file.
When the value of DEM Source is the name of an existing folder, the module searches that folder for a file named index.txt, and a set of DEM raster tiles. The index.txt file contains a single vector channel that lists the DEM files contained in the specified folder and provides information describing each DEM tile.
If no value is specified for this parameter, the module uses the default global DEM installed with CATALYST Enterprise (gmted2010).
Master Matching Channel
The channel from the input image to use for matching when collecting ground control points (GCPs). If no value is specified for this parameter, channel 1 is used, by default.
Reference Images
The path of a single reference image or a folder containing multiple reference images to be used for automatic collection of ground control points (GCP). Alternatively, you can enter a comma-delimited list of raster-image file names.
To use multiple GDB-supported geocoded reference images for automatic GCP collection, you can specify a reference-image folder (GDB-compatible) and an associated (GDB-compatible) digital elevation model for automatic GCP collection. The specified folder can contain multiple reference images to use for collecting GCPs.
The value of Reference Images is an image file that has been orthorectified previously for use with to automatic GCP collection. The GCPs collected from one or more of the reference images are stored in a GCP segment of the PCISDK image. The module also creates an OrthoEngine project that contains the same GCPs for quality- assurance (QA) tasks and manual editing.
When collecting GCPs using reference images, the module searches for ORTHO_X_ACCURACY and ORTHO_Y_ACCURACY metadata tags in the images. When such tags are present, the module uses those values to determine the accuracy of each GCP, thereby weighting the value of that point against others. The ORTHO_X_ACCURACY and ORTHO_Y_ACCURACY metadata tags are set in the Index PIX File Creator module. If no metadata tags are found in the reference image, the GCP accuracy is calculated to be half of the resolution of the reference image.
Reference Channel for Matching
The channel from reference image to use for matching when collecting ground control points (GCPs). Channel 1 is the default.
Sampling Method
The method to use to create ground control point (GCP) samples from the source imagery.
When collecting GCPs, the Grid option is recommended because the Susan option finds candidates on building corners that may not be represented in the digital elevation model (DEM), leading to GCPs with higher residuals due to height errors.
GCP Samples
The maximum number of ground control points (GCPs) to collect per reference image. For example, when a raw scene overlaps four reference images and you specify the value of this parameter as 50, the maximum number of GCPs collected is four times that value for a total of 200 (50 x 4 = 200).
If you are using the Grid option, available values are:
If using the Susan option, available values are:
Matching Algorithm
The algorithm to use for automated point matching.
When the two images being matched have similar gray values and appearances, Normalized Cross-Correlation (NCC) generally produces acceptable results. When there is a rotation or image-size error in the initial math models, NCC may produce better matching results than FFTP. Typically, this method also generates faster results, because the template size that NCC uses is smaller than that used by FFTP.
For more consistently accurate results, FFTP is recommended. This method uses a larger template size than NCC and, because it works in the frequency domain, it looks at the patterns of details in the image rather than the gray values in a small neighborhood, which NCC uses. This makes FFTP more robust than NCC when there is a large difference in brightness between images or when a major land-use change has occurred between the images. FFTP also allows for a better match between images of the same area from different sensors or spectral bands.
Collection Strategy
Number of passes in which to collect ground control points (GCPs) from reference images.
The first pass uses a coarse strategy, and the second uses a fine. When the input images are inaccurate, a two-pass strategy is recommended.
When the input data is geometrically close to the reference data, and for making final adjustments, a fine strategy is recommended.
While a fine strategy is the most accurate at collecting GCPs, it is slower than a coarse strategy.
When the accuracy of the input data is of poor quality, and to manually run two or more passes, a coarse strategy is recommended.
A coarse strategy adjusts the input data such that it is geometrically close to the reference imagery without too much overhead.
While a coarse strategy is faster than fine at collecting GCPs, it is less accurate.
Search Radius
The distance in the x and y directions from a starting location on the reference image over which the search for the best match with a fixed point on the input image is conducted.
The search radius is an estimation of error with the raw image's positional information and the digital elevation model (DEM) accuracy. If you know that your image is accurate to within 80 meters, and your DEM is accurate to within 200 meters, set the search radius to 280 meters. A larger search radius requires more processing time, because more locations are evaluated to determine the best match for a ground control point (GCP).
If this parameter is not specified, the function uses a default search radius based on the resolution of input data.
Minimum Score
The threshold value that controls whether a candidate ground control point (GCP) is accepted as a GCP or rejected. This parameter specifies the minimum-match quality that is considered acceptable, with 1.0 indicating a perfect match.
When using the Fast Fourier Transform Phase matching algorithm, this value is converted internally to a minimum acceptable phase-shift peak value.
When using the Normalized Cross-Correlation matching algorithm, this value specifies the minimum match score value required to accept a local match between the input and reference images as a GCP. The default value is 0.75.
Chip Database File
The path and file name of the chip database to use for automatically collecting ground control points (GCPs).
The module collects the GCPs from the chip database, and then automatically saves them to a GCP segment of the PCIDSK image associated with the GCP.
To improve the spatial accuracy of the collected GCPs, the chip database should contain high-quality image chips from a comparable sensor taken in similar conditions and be well-distributed over all of the scenes to be corrected.
Chip Channels
The number of the channels in the chip database to use for automated ground control point (GCP) matching.
Chip Matching Algorithm
The algorithm used for automated ground control point (GCP) matching.
Chip Search Radius
The distance in the x and y directions from a starting location on the reference image over which the search for the best match with a fixed point on the input image is conducted.
The search radius is an estimation of error with the raw image's positional information and the accuracy of the digital elevation model (DEM). For example, if you know your image is accurate to within 80 meters and your DEM is accurate to within 200 meters, set the search radius to 280 meters. A larger search radius requires more processing time, due to more locations being evaluated to determine the best match for a ground control point (GCP).
If no value is specified for this parameter, the module uses the same value specified for the Search Radius parameter.
Chip Minimum Score
The threshold value that controls whether a candidate ground control point (GCP) is accepted or rejected as a GCP. This parameter specifies the minimum match quality that is considered an acceptable match, with 1.0 indicating a perfect match.
When using the Fast Fourier Transform Phase matching algorithm, this value is converted internally to a minimum acceptable phase shift peak value.
When using the Normalized Cross-Correlation matching algorithm, this value specifies the minimum match score value required to accept a local match between the input and reference images as a GCP. The system default value is 0.75.
Road Network
The path to a vector file that contains the road-network layers to use for automatic collection of ground control points (GCP).
GCP collection from the road network extracts GCPs by matching an optical image with rasterized lines.
The GCPs are collected automatically by matching patches in the image with roads. Matching is performed in the spatial-frequency domain using Fast Fourier Transform (FFT) to transform and match image patches and rasterized lines. The matching algorithm is based on the Kuglin and Hines (1975) paper cited in the References section later in this topic.
In a typical application, between 100 and 200 GCPs are extracted, with most of them being correct. The GCPs can then be used in automated image-orthorectification workflows. This method is well-suited to midresolution images from 5 meters through 15 meters.
Road Width Field Name
The field name of an attribute in the vector segment. The field must contain one or two numerical values. The values are converted to a line width, in meters. Float, double, and integer fields are supported.
If this parameter is not specified, then the following field names are checked:
If none of these fields exist, then the Road Width Scale & Offset parameter defines the width of all lines in the file.
If the field does exist, and it contains a single value, then the scale factor part of the Road Width Scale & Offset parameter is used in the computation of the road width:
If the field exists, and it contains two values, then the two values in the Road Width Scale & Offset parameter are used to compute the road width:
Road Width Scale & Offset
The scale and offset, in meters, used in conjunction with the Road Width Field Name parameter to compute the road width in meters. This parameter contains one or two values. The first value, the road width scale (roadWidthScale), must be greater than zero. If specified, the second value, the road width offset (roadWidthOffset), must be non-negative.
If no value is specified for the Road Width Field Name parameter, the road width scale defines the width of all lines (in meters) in the file and the second value is ignored.
If a value for the Road Width Field Name parameter is specified, the scale and offset values are used to convert attribute values in the field to road width values, in meters. For more information, see the description of the Road Width Field Name parameter.
Polygon Vector File
The path to a file containing the polygon layers to be used for automatic collection of ground control points (GCP). The path may also specify a folder containing multiple polygon files.
GCP Text Files
The path and file name of a text file, or a folder of text files, that contains ground control points (GCPs) from other sources.
Each text file must have the MAPUNITS parameter specified in its required format. You can also specify up to two additional parameters, ELEVREF, and ELEVUNIT. The following table shows the supported values, a description, and an example for each parameter.
| Parameter | Supported values | Description | Example |
|---|---|---|---|
| MAPUNITS | PIXEL | Pixel and line | MAPUNITS=PIXEL |
| UTM | Universal Transverse Mercator | MAPUNITS=UTM 32 T D000 | |
| SPCS | State Plane Coordinate System | MAPUNITS=SPCS | |
| LONG/LAT | Longitude and latitude | MAPUNITS=LONG/LAT D000 | |
| METER | Image along-row and along-column, in meters | MAPUNITS=METER | |
| FEET | Image along-row and along-column, in feet | MAPUNITS=FEET | |
| ELEVREF | MSL | Mean sea level | ELEVREF=MSL |
| ELLIPS | Ellipsoid | ELEVREF=ELLIPS | |
| ELEVUNIT | METER | Meters | ELEVUNIT=METER |
| US_FEET | U.S. feet | ELEVUNIT=US_FEET | |
| FEET | Feet | ELEVUNIT=FEET |
When the path points to a folder, each text file must follow a naming convention, <filename>*GCP.txt, where <filename> is the file name of the ingested image.
GCP Text File Format
The format of the file or files specified for the GCP Text File parameter, if specified.
The available formats, including a link to an example of each, are as follows.
| Format | Example |
|---|---|
| 2D: ID P L X Y S |
|
| 2DERR: ID P L X Y eP eL eX eY S |
|
| 3D: ID P L X Y Z S |
|
| 3DERR: ID P L X Y Z eP eL eX eY eZ S |
|
| Bulk GCP File |
|
Water Mask File
The path to a file that contains the polygon water-mask layer to be used for refinement of ground control points (GCPs). The path can also specify a folder that contains multiple water-mask files.
Refine GCPs
Selected by default, this check box controls whether to refine the ground control points (GCP). Refinement is to systematically eliminate GCPs that have large errors. To retain the integrity of the GCPs you have imported or otherwise referenced in a text file associated with the project, clear the Refine GCPs check box.
Rejection Method
The method used to reject ground control points (GCP).
You can specify various values for this parameter, depending on the method selected.
Rejection Method Thresholds
The rejection threshold values for the value selected for the Rejection Method parameter.
Automatic: selects the most appropriate rejection method thresholds, based on the sensor of the input scene
RMS Error: rejection starts from the point with the largest residual error for any point, then recalculates the math model and RMS error. If the RMS error is still above the specified thresholds, the point with the next highest residual is removed and so on, until the x-RMS and y-RMS errors are equal to or less than THRESH1 pixels or THRESH2 pixels.
For example, a value of 2,2 rejects points with the highest residuals until the x-RMS and y-RMS are both less than two pixels.
Standard Deviation: THRESH1 and THRESH2 represent the minimum standard deviation values of the x and y residuals to be rejected, respectively.
For example, a value of 2,1 rejects points that have a standard deviation higher than two of the resX mean, and rejects points that have a standard deviation higher than one of the resY mean.
Percentage: THRESH1 represents the percentage of the number of points to be rejected and THRESH2 represents the ratio weighing between the x and y residuals. For example, if you set a rejection weight of 2, you are giving twice the weight to the x-residual (resX) as to the y-residual (resY). By default, the residual in x and y have the same weight. Therefore, if you have a point with a resX of 0.4 and a resY of 0.5, the point is given a resX of 0.8 and a resY of 0.5 for the rejection.
For example, a value of 5, 2 rejects five percent of GCPs, and gives the x-residual (resX) twice the weight as that of the y-residual (resY).
Absolute Distance: THRESH1 and THRESH2 represent the minimum absolute x and y pixel residuals to be rejected. The rejection starts from the point with the largest x or y residual distance.
For example, a value of 2,2 rejects points with a resX of greater than two pixels, and rejects points with a resY of greater than two pixels.
Absolute Number: THRESH1 represents the number of points to be rejected and THRESH2 represents the ratio weighing between the x and y residuals. For example, if you set a rejection weight of 2, you are giving twice the weight to the x-residual (resX) as to the y-residual (resY). By default, the residual in x and y have the same weight. Therefore, if you have a point with a resX of 0.4 and a resY of 0.5, the point is given a resX of 0.8 and a resY of 0.5 for the rejection.
For example, a value of 10, 0.5 rejects 10 GCPs, and gives the x-residual (resX) half the weight of the y-residual (resY).
Maximum GCPs
The maximum number of ground control points (GCPs) to accept.
After the module performs an initial collection of GCPs using the reference data, it refines the collection to ensure that only the most accurate points are retained.
If there are more GCPs collected than the specified maximum value, the module performs a second refinement, keeping only the GCPs with the lowest RMS error, up to the specified maximum number of GCPs. The second refinement uses the following rejection method:
RMS Error: for the second refinement, the rejection threshold value is set to the specified Maximum GCPs value.
Minimum GCPs
The minimum number of ground control points (GCPs) to accept.
After the module performs an initial collection of GCPs using the reference data, it refines the GCPs, and then verifies that the number of remaining GCPs is greater than or equal to the minimum number of GCPs.
RMS Error: for the second refinement, both rejection threshold values (THRESH1, THRESH2) are quadrupled.
For example, an initial threshold of 1,1 is relaxed to 4,4.
Standard Deviation: for the second refinement, both rejection threshold values (THRESH1, THRESH2) are quadrupled.
For example, an initial threshold of 2,1 is relaxed to 8,4.
Percentage: for the second refinement, the first rejection threshold value (THRESH1) is divided in half; the second (THRESH2) is left as is.
For example, an initial threshold of 10,2 is modified to 5,2.
Absolute Distance: for the second refinement, both rejection threshold values (THRESH1, THRESH2) are quadrupled.
For example, an initial threshold of 2,2 is relaxed to 8,8.
Absolute Number for the second refinement, the first rejection threshold value (THRESH1) is doubled; the second (THRESH2) is left as is.
For example, an initial threshold of 20,0.5 is modified to 40,0.5.
If there are still too few GCPs after the second refinement, the module aborts and displays an error message.
Collect Tie Points
Select this check box to collect tie points (TP) on valid overlapping scenes.
Sampling Method
The method to use to create tie-point samples from the source imagery.
For tie-point collection, the Susan option is often preferred because it facilitates performing quality assurance on the collected tie points: you can visualize a recognizable feature (perhaps a building corner or specific tree, for example) and compare it with the other image to see if it matches correctly.
TP Samples
The maximum number of tie points to collect.
When using the Grid option, acceptable values are:
When using the Susan option, available values are:
Trials per TP
The maximum number of attempts to find a match. The module attempts to match the primary sample point and, if that fails, selects alternate points within the same grid cell until a match succeeds or the number of trials is reached. The value you specify must be an integer ranging from 1 through 500.
Distribution Area
The area of each image in which to distribute tie points (TP).
Matching Algorithm
The algorithm to use for automated point matching.
When the two images being matched have similar gray values and appearances, Normalized Cross-Correlation (NCC) generally produces acceptable results. When there is a rotation or image-size error in the initial math models, NCC may produce better matching results than FFTP. Typically, NCC also generates faster results, because the template size it uses is smaller than that used by FFTP.
For more consistently accurate results, FFTP is recommended. This method uses a larger template size than NCC and, because it works in the frequency domain, it looks at the patterns of details in the image rather than the gray values in a small neighborhood, which NCC uses. This makes FFTP more robust than NCC when there is a large difference in brightness between images or when a major land-use change has occurred between the images. FFTP also allows for a better match between images of the same area from different sensors or spectral bands.
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.
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.
TP Rejection Method
The method used to reject tie points (TP).
You can specify various values for this parameter, depending on the method selected.
TP Rejection Method Thresholds
The rejection threshold values for the value selected for the Rejection Method parameter.
The maximum number of iterations is 10 when the number of TPs is less than 100,000, and five when the number of TPs is equal to or greater than 100,000.
RMS Error: rejection starts from the point with the largest residual error for any point, and then recalculates the math model and RMS error. If the RMS error is still above the specified thresholds, the point with the next highest residual is removed and so on, until the x-RMS and y-RMS errors are equal to or less than THRESH1 pixels or THRESH2 pixels.
For example, a value of 2,2 rejects points with the highest residuals until the x-RMS and y-RMS are both less than two pixels.
Standard Deviation: THRESH1 and THRESH2 represent the minimum standard deviation values of the x and y residuals to be rejected, respectively.
For example, a value of 2,1 rejects points that have a standard deviation higher than two of the resX mean, and rejects points that have a standard deviation higher than one of the resY mean.
Percentage: THRESH1 represents the percentage of the number of points to be rejected and THRESH2 represents the ratio weighing between the x and y residuals. For example, if you set a rejection weight of 2, you are giving twice the weight to the x-residual (resX) as to the y-residual (resY). By default, the residual in x and y have the same weight. Therefore, if you have a point with a resX of 0.4 and a resY of 0.5, the point is given a resX of 0.8 and a resY of 0.5 for the rejection.
For example, a value of 5, 2 rejects five percent of TPs, and gives the x-residual (resX) twice the weight as that of the y-residual (resY).
Absolute Distance: THRESH1 and THRESH2 represent the minimum absolute x and y pixel residuals to be rejected. The rejection starts from the point with the largest x or y residual distance.
For example, a value of 2,2 rejects points with a resX of greater than two pixels, and rejects points with a resY of greater than two pixels.
Absolute Number: THRESH1 represents the number of points to be rejected and THRESH2 represents the ratio weighing between the x and y residuals. For example, if you set a rejection weight of 2, you are giving twice the weight to the x-residual (resX) as to the y-residual (resY). By default, the residual in x and y have the same weight. Therefore, if you have a point with a resX of 0.4 and a resY of 0.5, the point is given a resX of 0.8 and a resY of 0.5 for the rejection.
For example, a value of 10, 0.5 rejects 10 TPs, and gives the x-residual (resX) half the weight of the y-residual (resY).
Pansharpen Order
The order in which to perform pansharpening.
Pansharpening Method
The method to use for pansharpening.Multispectral Sharpening Channels
A comma-delimited list of the multispectral channels to sharpen.
If no value is specified for this parameter, all channels are processed by default. These channels are fused with the high-resolution, panchromatic image data.
Multispectral Reference Channels
A comma-delimited list of the multispectral channels to use as reference for the sharpening process.
If no value is specified for this parameter, all channels are processed by default. These channels, and those of the panchromatic image, span the same range of frequency (wavelength) response.
When no reference channel is specified, the module determines the appropriate reference bands based on the available wavelength information for both the panchromatic and multispectral files.
Resampling Method
The resampling method to use during processing.
Enhance
Specifies whether to generate a refined pansharpened image.
The enhance option is only available for UNB pansharpening.
Edge Sharpen
Amount of sharpening to image edges to apply. A value of 1.0 (default) means no edge sharpening. Values greater than 1.0 apply greater sharpening. Values greater than 2.0 are not recommended.
Applying edge sharpening makes image more visually appealing but may degrade radiometric similarity with the original multispectral (MS) data.
AdaptRadiometry
Method to adapt the output spectral values to those of the input multispectral (MS) image.
Adapting the radiometry can better match to the original multispectral image. The two methods are linear regression based on a small sliding window and an estimate of the Modulation Transfer Function (MTF).
Output Map Units
The projection of the output imagery.
The value of this parameter must be in the PCI Projection String format.
UTM: Universal Transverse Mercator
The value specified can be the UTM grid zone number and row, and Earth model, as follows:
UTM [mm] [r] [Ennn]
SPCS: State Plane Coordinate System
The SPCS zone number and Earth model can be specified as follows:
SPCS [mmmm] [Ennn]
LONG/LAT: Longitude and latitude
The Earth model can be specified for LONG/LAT (and other units except PIXEL), as follows:
LONG/LAT [Ennn]
If the Earth model is not specified, it is assumed to be E000 (Clarke 1866).
EPSG: European Petroleum Survey Group code
You can specify the projection by entering an EPSG code defined by the Open Geospatial Consortium (OGC). For information on the code definitions, visit epsg.org and spatialreference.org.
The EPSG code is specified using the EPSG keyword followed by an integer and separated by a colon; for example:
EPSG:4326
Most common EPSG codes are supported.
METER: Image along-row and along-column meters
FEET: Image along-row and along-column feet
LCC D350 | 0 0 3.0 46.5 44.0 49.0 700000 6600000 0 0 0 0 0 0 0 0 0 -1
If you do not specify a value for Output Map Units, the map unit of the input image is used for the output image. If the input data is a variety of map units, the map unit of each output image is that of its corresponding input image. In such a case, it is recommended that you specify the output map units.
You can also specify the label of a projection defined in the userproj.txt file.
Panchromatic Pixel Output Size
The output spatial resolution for the panchromatic imagery to be orthorectified.
The units for the pixel size must match the units selected for the Map Units parameter; for example, if the map units are specified as UTM, the panchromatic pixel output size is in meters.
If no value is specified for this parameter, the pixel output size is based on the input math model associated with each scene in the input-scenes folder.
Multispectral Pixel Output Size
The output spatial resolution for the multispectral imagery to be orthorectified.
The units for the pixel size must match the units specified for the Map Units parameter; for example, if the value of Map Units is specified as UTM, the multispectral pixel output size is in meters.
If no value for this parameter is specified, the pixel output size is based on the input math model associated with each scene in the input-scenes folder.
Resampling Method
The resampling method to use during processing.
Resampling Method Extra Options
SHAPINGWINDOW=[sw],BETA=[beta]
where:
SHAPINGWINDOW specifies a window to attenuate the SINC coefficients to reduce resampling artifacts. The value can be KAISER, HAMMING, HANN, LANCZOS, PARABOLA, or NONE. SHAPINGWINDOW is optional; the default value is KAISER. BETA is applicable only when SHAPINGWINDOW is KAISER. SHAPINGWINDOW determines the shape of the KAISER window; a larger BETA value produces greater attenuation of the SINC coefficients. Its value can be between 1.0 and 10.0. BETA is optional.
NUMCOLS=[nc],NUMROWS=[nr]
NUMCOLS=[nc],NUMROWS=[nr]
where:
NUMCOLS and NUMROWS can be any value between 1 and 11.
DSFACTORCOL=[dc],DSFACTORROW=[dr]
where:
DSFACTORCOL is the fraction downsampling factor in col (>=1). If not specified, a default factor is computed automatically based on the output and input pixel sizes. DSFACTORROW is the fraction downsampling factor in row (>=1). If not specified, default to the value of DSFACTORCOL.
Sorting Method
The order in which the images is sorted and added to the mosaic.
Starting Image
When you select Nearest to Center or Maximum Intersection for Sort Method, the first image to add to the mosaic.
If you do not specify a starting image, the image that is most central is processed first.
When you select None for Sorting Method, this parameter is ignored.
Normalization Method
The normalization to apply to each source image before color balancing, cutline generation, or mosaicking.
When Hot Spot is selected as the normalization method, hot spots are removed from the images by normalizing the brightness over the image by fitting a Gaussian surface to the brightness values. It does not remove the smaller spot reflections from lakes, cars, or buildings.
The adaptive filter adjusts the brightness and contrast over local areas, thereby improving image detail, while reducing the bright-and-dark pattern over the entire image. It applies an adaptive enhancement using a moving window to calculate the adjustment for each pixel value. The filter calculates the mean and standard deviation of the gray levels within the window and adjusts the values to match the overall mean and standard deviation of the image. The mean is used to adjust the brightness and the standard deviation is used to adjust the contrast.
Normalization Method Extra Options
When you select Adaptive for Normalization Method, you can define additional options for normalization.
To define the filter size for the adaptive normalization, enter the image_percent value to use
The default is 20 (20 percent).
Color Balancing Method
The color-balancing method to apply to the final mosaic.
Color balancing evens out the color contrasts from one image to another to reduce the visibility of the seams and produce a visually appealing mosaic. All color-balancing methods (except None) result in some parameters that define an adjustment of pixel values in the source image. The adjustments are applied when the image is added to the mosaic and stored as part of the mosaic project.
Color Balancing Extra Options
Additional color-balancing options. The options apply to the Bundle, LUT, Histogram, Reference, and Neighborhood color-balancing methods.
Autoscale can be specified for all input images to be stretched linearly and have a common scale. This can improve the results when different input images have significantly different dynamic ranges.
LUT: <LUT_segment_number>
LUT_segment_numbers explicitly specify the LUT-segment numbers to use for color balancing. The first LUT is used for the first image channel, the second LUT for the second channel, and so on. All input images must have the specified LUT segments; otherwise processing of the job stops and a message detailing the event appears.
Reference: <fili_ref>
fili_ref specifies the reference image file
Global Color Balance Mask File
The file used to define a global color-balance mask, which identifies regions in the source images to omit from any color-balancing computation.
A global mask is useful when imagery contains, for example, massive water bodies. The global color-balance mask applies to all images in the mosaic project.
If you specify a value for this parameter, you must specify a value for Global Color Balance Mask Layer.
Global Color Balance Mask Layer
The layer in file specified for Global Color Balance Mask File that contains a global color-balance mask identifying regions in the source images to omit from any color-balancing computation.
Global Color Balance Mask Segment
When Specific Segment is selected for Global Color Balance Mask Layer, this parameter specifies the number of the segment that contains polygons or bitmaps to use to mask pixels during color-balancing calculations.
Cutline Method
The cutline method used to generate polygons that enclose all the data from an image to be included in the output mosaic.
Cutline Method Extra Options
Additional options for Cutline Method.
You can specify options related to constraining polygons, which define regions where cutlines are allowed for each image, so that the generated cutlines do not cross the specified boundaries.
Values you specify for this parameter take precedence over Auto Constrain and Factor.
[<vector_file>], [<field_name>], [<segment_number>]
If the field_name is not specified, MOSPREP searches the vector-segment attributes for a field named ImageSource. If the specified field name or ImageSource does not exist, an error occurs.
If the segment number is not specified, the algorithm uses the last segment from the vector file you specified. If the constraining polygon is larger than the image being processed, cutline generation is not constrained.
Auto Constrain
Select whether and how to automatically generate and apply constraint polygons when creating cutlines. Constraint polygons define regions where cutlines are allowed for each image, so that the generated cutlines do not cross the specified boundaries. You can opt to have them generated automatically based on the layout and arrangement of the images being mosaicked.
You can adjust the effect of Auto Constrain by specifying an appropriate percentage value for Factor.
When a constraining layer is specified for Cutline Method Extra Options, do not use Auto Constrain; that is, select No.
Factor
The Factor is a percentage by which to adjust effect of the Auto Constrain option.
This is a value between 1 and 100, with larger values causing more overlap between the generated constraint polygons; that is, the cutlines is less constrained.
Simplify Cutlines
Selected by default, this check box causes the module to simplify the cutlines for the mosaic. Simplification is to remove unsuitable vertices from the cutline shapes computed initially.
You can use this parameter in conjunction with Simplification Level to set the degree of simplification you want.
Simplification Level
Available when the Simplify Cutlines check box is selected, you can set the level of simplification you want to use.
When the Simpify Cutlines check box is clear, no simplification level is applied. When the check box is selected, a default value of 1.75 for Simplification Level is applied; otherwise, the value you specify is applied.
To create cutlines from all of the vertices computed initially, enter a value of 0. A number greater than zero increases the amount of vector reduction; the cutlines will have fewer vertices. Generally, a value of n results in 1/n of the vertices being computed. For example, a value of 2 results in approximately one half of the vertices.
Global Cutline Avoidance Mask File
The file that, in conjunction with Global Cutline Avoidance Mask Layer and Global Cutline Avoidance Mask Segment, can be used to identify common regions in all source images to omit from cutline calculations. When a global cutline-avoidance mask is used, the image pixels in the masked regions are excluded from the cutline calculations wherever possible; if there is no better area in which to place a cutline, the cutline passes through the masked region.
When you specify a value for this parameter, you must also specify a value for Global Cutline Avoidance Mask Layer.
Global Cutline Avoidance Mask Layer
The layer in the file specified for Global Cutline Avoidance Mask File to use as the global cutline-avoidance mask. When no value is specified for Global Cutline Avoidance Mask File, this parameter is ignored.
Global cutline-avoidance masks are used to restrict specific areas from cutline calculations; for example, to avoid cutlines crossing through buildings. When a global cutline-avoidance mask is used, the image pixels in the masked regions are excluded from the cutline calculations wherever possible; if there is no better area in which to place a cutline, the cutline passes through the masked region. A global cutline-avoidance mask applies to all source images that intersect the global mask layer.
Global Cutline Avoidance Mask Segment
When Specific Segment is selected for Global Cutline Avoidance Mask Layer, this parameter specifies the number of the segment that contains polygons or bitmaps to use to mask pixels to avoid when calculating cutlines.
Area of Interest File
A file that contains a single vector layer that defines the area to which the output mosaic is clipped.
The vector layer can contain one or more polygons.
Crop Tiles to AOI
Selected by default, this check box controls whether to crop the tiles to the area of interest (AOI) during processing.
Tile Base Name
The base name for file names of all tiles created during the mosaicking process.
Tile Specification
The tiling scheme to use for the output mosaic.
Height
The height of the mosaic tile, in pixels.The union of the extents of all of the source images is divided into a series of evenly sized and abutting rectangular tiles with the specified dimension.
Only tiles that actually intersect at least one of the source images is present in the output. The tiles at the far right and on the far bottom may overhang the extents of the source images. This is done to ensure that all tiles have the same dimensions.
TileID values are generated using the convention <column_number>_<row_number>. For example, the upper-left tile always has a TileID of "1_1", while the one immediately below it is "1_2", and so on.
For example:
10000
Width
The width of the mosaic tile, in pixels.The union of the extents of all of the source images is divided into a series of evenly sized and abutting rectangular tiles with the specified dimension.
Only tiles that actually intersect at least one of the source images is present in the output. The tiles at the far right and on the far bottom may overhang the extents of the source images. This is done to ensure that all tiles have the same dimensions.
TileID values are generated using the convention <column_number>_<row_number>. For example, the upper-left tile always has a TileID of "1_1", while the one immediately below it is "1_2", and so on.
For example:
10000
Vertical Overlap
The vertical overlap of each tile, in pixels.
Horizontal Overlap
The horizontal overlap of each tile, in pixels.
Tile File
The name of the text file containing the tile-definition layer.Each line in the text file contains five elements separated by spaces: the first two define the upper-left coordinate in the x and y dimension, respectively. The next two define the lower-right coordinate in the x and y dimensions, respectively. The last one specifies the output file name of the tile. If the file name includes an extension, the extension is removed when the value is stored as the 'TileID' attribute in the tile-definition polygon. If the file name includes a path, the entire path is transferred and appended to the output folder.
The RASEXT and RASOFFSZ coordinate types make use of pixel/line raster, as defined by the union of the extents of all input source images. If a coordinate type is not specified, it is assumed to be GEOEXT. For example:
Segment Number
In the tile file you specified, the number of the vector segment to use. If no segment number is specified, the last segment in the specified tile file is used.Field Name
Name of the field (attribute) that has unique identifiers for each tile. The module uses the values in the field to form the names of the mosaic tile files. If no field name is specified, the attribute ShapeID is used.Coordinate Type
When Tile Specification is Script File, the type of coordinates in the script.
Tile Position Transformation
With this parameter you can define a grid where each top-left corner of a tile is aligned to one of the vertices in the grid.
These values define the position of the corner or center in the raster grid.
Of the four values, only Stride_X is required. If not specified, Stride_Y defaults to the Stride_X value, and Ref_X and Ref_Y default to zero.
In the following example, the upper-left corner of the upper-left pixel of each tile is an even 20-meter multiple from the reference point (432345.000, 5438882.000). Depending on the distance of the tile from that point, its upper-left corner coordinate could be 432345.000, 432045.000, or any other multiple, but is never 432346.000 or 432355.000.
Example:
"CORNER, 20, 20, 432345.000, 5438882.000"
If specified, this parameter is applied in all scenarios, whether the image-corner coordinates come from the input file (MFILE), ULX and ULY, or through automatic computation.
Blend Width
The perpendicular distance from the cutlines over which image blending occurs.
Image blending is to average the gray value of each pixel in the blending strip along a cutline from both overlapping input images. If no value is specified for this parameter, no blending is performed.
Create Source Map
Select this check box to create a source map on output along with the mosaic.
A source map is a polygon layer created and stored in a separate file, which contains an attribute that identifies the predominant source input image used for each pixel in the output mosaic. As images are added to the mosaic, the source image is recorded in a separate raster, which is converted to a polygon layer at the end of the process.
The source map layer is created in a file with the same name as the output mosaic file(s), but with _SourceMap.pix appended to it.
Existing Tile Rule
Select an action to perform when an output tile already exists.
Available options are:
Skip: No change is made to the existing tile and no new processing is performed. This option is useful when you do not want to modify your existing mosaic output.
Delete Empty Tiles
Select whether to delete empty tiles. A tile is considered to be empty if all pixels in it have the value defined as NoData.
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Preprocessing requirements
Before running this module, the following requirements must be met to ensure the job processes successfully and produces accurate results:
Module details
The Mosaic from Raw Scenes module imports satellite imagery into CATALYST Enterprise for processing and produces output mosaic images.
About GCP collection on road vectors
This module extracts ground control points (GCPs) by matching an optical or SAR image with rasterized lines.
The module is designed to extract GCPs from road vectors in medium-resolution images with resolutions from about 4 meters through 15 meters. It models each road as a ribbon with a sinc-like cross-section. The ribbon is either dark on a uniform bright background, or bright on a dark background. The width of the ribbon is either set explicitly or derived from attributes of each road segment, such as the number of traffic lanes.
This model works very well for mid-resolution images, such as SPOT and Landsat 7 PAN, and provides GCPs accurate to about 1 pixel, or within 5 meters through 10 meters. PCI extended to higher-resolution images by averaging the images down to the matching resolution of 3 meters through 6 meters. The matcher can also be directed to try both bright-on-dark or dark-on-bright matches at every point, and then select whichever one is better.
Inherent accuracy of road vectors
This factor alone limits the achievable accuracy of GCPs extracted from road vectors. Canadian experience shows that most road vectors have an accuracy of about 5 meter through 10 meter; for example, the current Canadian national road network claims an accuracy of 6.5 meters. In addition, many road vectors are less accurate, or even in disagreement with the images, due to rapid land-use changes in many areas. The road GCP module can even cope with large inaccuracies, or fail for such GCPs, but the overall achievable accuracy is limited.
Road model used
The "smooth-ribbon" model is well suited to mid-resolution images, particularly in non-urban areas. However, it becomes inadequate at higher resolutions due to other details in the images, such as vehicles, street furniture, road markings, vegetation, and building and tree shadows. Objects such as these introduce significant clutter, and lower the overall accuracy of the matches. These matches are often rejected. If they are not rejected, the matcher settles on nearby, more uniform linear objects, such as bright rooftops of large buildings or their shadows.
Varied appearance of roads
The roads may not be uniformly brighter or darker than their surroundings, as the model assumes. Their appearance depends on the spectral bands of the matched image, type and age of the road-surface material, season (snow versus no snow), and even the moisture content. In many images, roads are mid-gray, and, in such a case, are not handled well by the tool.
Significant building lean in urban scenes
High-resolution satellites fly at lower altitudes and, therefore, introduce a higher degree of building lean. Some images can also be taken in off-nadir orientation, which magnifies this effect even more. In urban areas, leaning buildings often obscure streets, at which point the matcher either fails or matches incorrect features.
Elevated highways
In most instances, the elevations of GCPs are extracted from a bare-earth digital elevation model (DEM), while some of the GCPs can be extracted from elevated highways, bridges, or multilevel highway intersections or interchanges. Such features are matched correctly in the image space, but have incorrect (ground) elevations, which leads to biased GCPs and an inaccurate refined model.
All of the preceding factors contribute to the lowered accuracy of road GCPs in high-resolution images, and limit their accuracy to the 5-meter through 10-meter range. They also introduce a possibility of systematic biases, particularly along the viewing direction of the satellite.
Road GCPs extracted from high-resolution images are still useful if the biases in the original (nominal) model of the scene exceed 10 meters through 5 meters. However, if the nominal model is already accurate to greater than 10 meters, the model refined with the road GCPs may be less accurate than the nominal one.
Images with resolutions outside the optimum range will be processed, but the results may be unsatisfactory: few extracted GCPs for low-resolution images, and many incorrect matches for high-resolution images. The module issues a warning for images with pixel sizes less than 1.9 meters.
Naming convention for GCP IDs
Each GCP collected has an ID. The naming convention of the ID is described in the following table, where the GCP ID is: XXXXXXXX_YYYY_N.
| GCP ID element | Description |
|---|---|
| XXXXXXXX | Hash code of the input image |
| YYYY | Hash code of the reference data |
| N | Number of the GCP, one to any number |
Job results
For each raw scene found in the input scenes folder, the Mosaic from Raw Scenes module creates a series of output files in the subfolders of the specified output folder, depending on the options specified for the module parameters. For example, if you specified tiled output, the output folder will contain the mosaicked result in a series of tile files. The file names for the tiles are created automatically according to the specified base name and location or vector-file field name.
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Kuglin, C.D. and D.C. Hines (1975). "The phase correlation image alignment method." Proceedings of the IEEE 1975 International Conference on Cybernetics and Society, San Francisco, California, 163-165
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