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| Name | Caption |
|---|---|
| Reference Image | File name of the reference image |
| Input Images | Name of a file or folder of images to desaturate |
| Search Pattern | Pattern for file searching |
| 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 |
| Desaturation Level | Level of desaturization to apply |
| Desaturation Amount | Amount of custom desaturation to apply |
| Desaturation Percentage | Percentage of custom desaturation to apply |
| Raster Channels | List of channels |
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Reference Image
The name of the reference-image file on which to base desaturation statistics. Typically, this file is a full-mosaic overview. The channels in the reference image are assumed to have a one-to-one correspondence in type and order with the input images, though they can be at different resolutions.
If the reference image is the name of a SILFILE XML file created by the Mosaic Preparation module, then its mosaic preview is used.
This parameter is mandatory.
Input Images
The name of a file or folder of images to desaturate. All input images must have the same projection as the reference image and be completely inside the area covered by the reference image.
If the reference image and input image are the same, then the reference image is desaturated.
If the input image is the name of a SILFILE XML file produced by the Mosaic Preparation module, then its mosaic preview is used. Running the Image Desaturation module on the mosaic preview provides a quick way to evaluate how the final mosaic will look without having to process the entire mosaic.
This parameter is mandatory.
Search Pattern
The search pattern to use when scanning the folder of reference imagery.
For example, to search PCIDSK files, you can specify *.pix, or to search .TIFF (or .tif) files, you can specify *.tiff or *.tif, as applicable. You can also combine two or more patterns separated by a comma, such as *.pix, *.tif.
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.
Desaturation Level
The preconfigured desaturation level to apply to the input images.
Desaturation Amount
The amount (or aggressiveness) of desaturation to apply when you select Custom for the Desaturation Level parameter. This relates approximately to the amount (area) of the image that can be modified. The range of values is from 1 (apply almost no desaturization) to 99 (desaturate virtually the entire image). A high value, such as 50, desaturates all bright and semi-bright areas. A low value, such as 5, means only a small number of very bright areas will be modified. Starting with a lower value is recommended.
Desaturation Percentage
Percentage of bright-area pixels to desaturate. Of the bright pixels identified as candidates, those that occur below the specified percentage will not be modified, while those above may be tweaked. The range of values is from 1 (virtually no bright areas are modified) to 99 (almost all bright areas will be modified). A higher value means more modification and results will be more substantial. A low value, such as 10, means only subtle changes will occur. The default value is 50, which means half of the pixels in the bright regions will be modified.
Raster Channels
A comma-delimited list of channels; for example, 1,2,5.
This parameter is optional. If you do not specify a value, all of the channels in the input files is used.
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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 Image Desaturation module was developed specifically to create better-looking mosaics, but it can be used to adjust overly bright areas in any image. Images often have large overly bright (or saturated) areas in which detail appears "washed out" when an enhancement (LUT) is applied. Typically, such areas are quarries, beaches, building roofs, parking lots, and so forth.
Attempting to bring out detail in the washed-out areas by darkening them usually results in an image that is unacceptably darker overall. The Image Desaturation module solves this problem by identifying washed-out areas and adjusting the data values in these areas without modifying the surrounding areas. When an enhancement is applied to this modified image, the washed-out areas will have more detail. The overall radiometry of the image is not affected.
Image Desaturation module is suited ideally to large image mosaics as a post-processing step. The mosaic overview (created typically with the Mosaic Preparation module is used to derive global statistics and control the processing of the full-resolution mosaic tiles.
Job results
During processing, a desaturation-ref folder is created in the output folder. The folder contains a PIX file linked to the reference file. Desaturation statistics and pyramids are generated in the linked PIX file.
When the output folder is different than the input folder then the output folder is populated with the desaturation results. The output filenames are the same as the input file names.
Output files are created automatically with the same projection, extents, and metadata as the input files. Output files are pyramided.
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