Pansharpening module

Name	Caption
PAN Input Folder	Input panchromatic image folder
MS Input Folder	Input multispectral image folder
Output Folder	Output folder
Output File Type	Output file type
Output File Options	Output file options
Overwrite Results	Overwrite existing results
Send Email	Email notification settings
Source Background Type	Source background type
Source Background Value	Source background pixel value
MS/PAN Pair Matching Direction	Direction of matching MS/PAN pairs
Match By Overlap	Whether to match by overlap when no naturally matching image is found
Merge Matches	Whether to merge multiple intermediate pansharpened images
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

Parameter descriptions

PAN Input Folder

The path and name of the folder that contains panchromatic imagery to pansharpen.

Input panchromatic images must be either:

Orthorectified using the Orthorectification module
Capable of pansharpening from raw imagery (before orthorectification), but previously imported to PCIDSK using the Data Ingest module

This parameter is mandatory.

MS Input Folder

The path and name of the folder that contains multispectral data to pansharpen.

This parameter is mandatory.

Output Folder

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

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.

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.

Available options are:

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.
None: all pixels in the source image are to be considered valid
All: if the pixel value in all channels matches the values provided for the Source Background Value parameter, the pixel is considered background (NoData).
Any: if the pixel value in any channel matches the value provided for the Source Background Value parameter, the pixel is considered background (NoData).

For specific examples, see the Source Background Value parameter description.

Source Background Value

The source background value or values when the Source Background Type parameter is set to:

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.

The following examples apply to a 3-channel, 8-bit unsigned image:

Source Background Type set to All and Source Background Value set to 0: a pixel is considered background if all three channels are zero.
Source Background Type set to Any and Source Background Value set to 0: a pixel is considered background if any of the three channels is zero
Source Background Type set to All and Source Background Value set to 128,0,0: a pixel is considered background if its value is exactly 128 for the first channel and zero for the second and third channels
Source Background Type set to All and Source Background Value set to 128,0,0,245: a pixel is considered background if its value is exactly 128 for the first channel and zero for the second and third channels. The value 245 is ignored.
Source Background Type set to Any and Source Background Value set to 128,0: a pixel is considered background if the value in channel 1 is 128 OR if the value in channel 2 or 3 is zero.
Source Background Type set to Any and Source Background Value set to 1032,0: a pixel is considered background if the value in channel 1 is 255 OR if the value in channel 2 or 3 is zero. The first value is truncated to the range allowed for 8U data.

MS/PAN Pair Matching Direction

Available options are:

Match PAN with MS - a child Pansharpening job is spawned for each PAN image in the Input Folder. The child jobs find the matching MS images.
Match MS with PAN - a child Pansharpening job is spawned for each MS image in the Input Folder. The child jobs find the matching PAN images.

The matching direction selected affects the number of child jobs spawned and the merged PSH files produced.

Match By Overlap

If the Match By Overlap check box is checked and the parameter MS/PAN Pair Matching Direction is set to:

Match PAN with MS - the PAN images that do not have a naturally matching MS image, will be matched against all MS images that overlap the PAN.
Match MS with PAN - the MS images that do not have a naturally matching PAN image, will be matched against all PAN images that overlap the MS.

If the Match By Overlap check box is unchecked then only naturally matching MS/PAN pairs produce a pansharpened image.

Naturally matching MS/PAN pairs are those where the MS and PAN images were taken at the same time, or nearly the same time, and are distributed together, as a package, with the raw vendor data.

Merge Matches

When the Merge Matches check box is checked, a child job will merge all PSH files it produces into a single PSH file and discard the individual PSH files. When the Merge Matches check box is unchecked the individual PSH files produced by a child job are kept.

This parameter is only relevant when the parameter Match By Overlap is checked.

Pansharpening Method

The method to use for pansharpening.

Available options are:

MRA Fusion: creates high-resolution color images by fusing black-and-white panchromatic and multispectral color images by using wavelet decomposition.
UNB Pansharp: developed by the University of New Brunswick, this method creates high-resolution color images by fusing black-and-white panchromatic and multispectral color images. The method uses an algorithm that produces sharpening results superior to other types while preserving the spectral characteristics of the original images.

With either method, both 8-bit and 16-bit data types are supported, and the images can be from the same or different sensors.

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.

Note: You cannot specify duplicate channels.

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.

Note: You cannot specify duplicate channels.

Resampling Method

The resampling method to use during processing.

Available resampling options are:

Cubic: cubic convolution. This method determines the gray level from the weighted average of the 16 pixels closest to the specified input coordinates and assigns that value to the output coordinates. The resulting image is slightly sharper than one produced by bilinear interpolation.
Bilinear: bilinear interpolation. This method determines the gray level from the weighted average of the four closest pixels to the specified input coordinates and assigns that value to the output coordinates. An image with a smoother appearance than nearest-neighbor interpolation is created, but the gray-level values are altered in the process, resulting in blurring or degraded image resolution.

The resampling method is only available for UNB pansharpening.

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).

Available options are:

YES: applies both the MTF and LIN options (default)
ALL: applies both the MTF and LIN options (default)
MTF: applies MTF
LIN: applies Linear
NO: no adapting radiometery applied

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:

When the input data sets do not support pansharpening of raw imagery, ensure that the imagery in the input folder has been orthorectified already and processed by using the Orthorectification module. This ensures that the multispectral (MS) and panchromatic (PAN) image scenes are properly aligned to each other, rendering a more accurate pansharpened image product.
When the input data sets support raw imagery pansharpening, ensure that the imagery in the input folder has been processed already by the Data Ingest module or the Data Ingest and GCP Collection module. This ensures that the imagery has been imported correctly, and that any GCPs present in the raw imagery are transferred correctly to the output pansharpened image products.

Module details

The Pansharpening module automatically creates pansharpened image products from a variety of input imagery. For example, you can create pansharpened image products from input orthorectified MS and PAN image pairs. Alternatively, you can also create pansharpened image products from input raw MS and PAN image pairs, for sensors supporting this capability.

Because there are various methods of pansharpening data available, the point at which you use this module varies; for example, when the raw imagery supports pansharpening, you can use the module immediately after running the Data Ingest module, and before the Orthorectification module. When the imagery must be pansharpened after orthorectification, use the Pansharpening module immediately after executing the Orthorectification module. In some cases, you may not need to pansharpen data at all.

With the Pansharpening module, you can produce a high-spectral resolution image with the high-spatial resolution provided by a corresponding panchromatic image.

The output pansharpened image products will be a single file for each MS-PAN image pair.

The Pansharpening module supports processing using GPUs and multi-core processors.

Job results

For each image pair found in the input folder, the Pansharpening module creates a single pansharpened PCIDSK file.

Output image file names are structured as follows:

<SCENE_ID>_<STATE>_PSH.pix

where:

SCENE_ID: the scene ID of the image for the pansharpened image
STATE: indicates the current state of the image (ORTHO or RAW)
PSH: indicates that the output image is pansharpened

Output images are located in the folder specified for the Output Folder parameter.

This module transfers file-based metadata tags from the source files to the output. The transferred metadata information includes the date and time that the input scene was acquired, the sensor or platform name, and the ID of the scene.

The following metadata tags are transferred to the output:

Acquisition_DateTime
Acquisition_Date
Acquisition_Time
sensor
platform
PlatformName
PlatformNumber
sceneId

Pansharpening module

Description

Parameters

Parameter descriptions

Details