Isis 3 Application Documentation
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Create a mosaic using a list of map projected cubes
This program uses a text-based list of cubes, all in the same map projection and equivalent projection parameters (PixelResolution, CenterLongitude, LatitudeSystem, etc), to generate a mosaic. By default, The program automatically determines the size of the mosaic by examining each cube. The user also has the option of entering their own lat/lon range to use for the mosaic.
There are four different ways/priorities (input, mosaic, band, average) for how the input image has to be placed on the mosaic.
Priority Input will place the input image on top of the mosaic.
Priority Mosaic will place the input image beneath the mosaic.
Priority Band will place the input image on the mosaic based on the "Lessser" or "Greater" criteria between user defined band in the input and the mosaic images.
Priority Average will average the valid pixels in the input and mosaic images. For each mosaic band, a count band is maintained. The count band keeps track of the number of images involved in the averaging of the dn value for each pixel in the mosaic. Choosing this priority will cause the mosaic to have twice the number of bands of the input image, with a count band for each band. Hence the file size of the mosaic is doubled due to the count band.
In case of special pixels and the special pixel flags being enabled, the details for each priority is described below.
Tracking can be set at the time of Mosaic creation only and cannot be turned on after the mosaic is created. But the tracking will be turned off for multiband ONTOP and BENEATH priority even though it was turned on while creating the mosaic. Tracking for multiband input with ONTOP priority is possible only if all the Special Pixel Flags are set to True else the Tracking will be turned off. ONTOP priority basically places all the valid input pixels onto the mosaic unless the special pixel flags are turned on or if mosaic has a NULL pixel. In a multi band scenario, a pixel origin in particular line and sample will not be the same in all the different bands, which means we have to keep track of every pixel in every band. i.e. the size of the tracking bands will be the same as the number of bands in the mosaic.i.e the number of bands will be doubled.
WARNING: If Tracking is turned on in a mosaic, any subsequent applications that modify "dn" values will corrupt the Tracking band. It may be necessary to remove the Tracking band from the mosaic and then add it back after all the processing is complete. See "crop" and "cubeit".
Priority BAND can track origin for multi band input image based on a specified band using LESSER or GREATER than criteria. Each pixel in the specified band is compared to the corresponding pixel in the chosen band in the mosaic based on the chosen criteria. This comparison true or false is used for all the other bands whether the input pixel is copied onto the mosaic and hence the origin for that pixel is stored. Band can be chosen by choosing the TYPE, BANDNUMBER or KEYWORD. If BANDNUMBER is chosen then the band number can be entered in the NUMBER field. If KEYWORD is chosen then PVL key name and value from the BANDBIN group can be entered in the KEYNAME and KEYVALUE fields.
For example, for a multi band input with BAND priority, if the BAND chosen is Emission Angle band(EMA), if input pixels are (30,30,30) in EMA Band for some sample, line and the corresponding pixels in the EMA band in the mosaic has (75, 75, 75) and the criteria is GREATER than, then since input pixels are not GREATER than corresponding mosaic pixels, then the input pixels are not copied to the mosaic, so also the corresponding pixels in all the other bands in the input. Hence the origin for those pixels remains unchanged. If LESSER than was the criteria, then all the corresponding pixels in all the input bands will be copied to the mosaic and the origin for those pixels is the current input image.
There are options like MATCHBANDIN, if set requires the specfied input bands to match the mosaic bands and the bands can be anywhere in the mosaic but must be contiguous for multi-band. If MATCHBANDIN is not set then any input image can be placed on the mosaic within it's boundaries.
Options HIGHSATURATION, LOWSATURATION and NULL if set will cause the the input pixels with these values to be copied to the mosaic for ONTOP and BAND priorities regardless of the CRITERIA for the BAND priority. These options are not supported for BENEATH priority.
Currently Tracking can be viewed in the Advanced Tool Tracking option of the qview application. Following are the Tracking info:
Index : Zero based and is in the order in which the image was placed on the mosaic. No origin is represented as -1.
FileName: File name of input image
Serial Number:Serial Number of the input image
Following are the values for the origin band depending on the pixel type
Following is the table for Special Pixel options, input, mosaic
pixels and the resulting output for different priorities.
A list of map projected cubes to mosaic. The Mapping groups must match in order to mosaic the cubes.
|Filter||*.txt *.lis *.lst|
The mosaic cube which will have the input cube placed into it.
This optional output list contains the names of all images that were added onto the mosaic.
This parameter is used to select one of three ways to mosaic the pixels in areas of overlap.
The pixels in this band will be used for comparison between input image and the mosaic for a decision to be made in copying image into the mosaic.
The band number should match that in the "OriginalBand" of "BandBin" Group
The entered key name must match the key name in the "BandBin"
This value must match the value associated with the key name entered in the KEYNAME
This parameter is used to select one of two ways to mosaic the pixels in areas of overlap when doing by band comparison.
The ground range can either be calculated automatically or entered by the user. If the USER option is selected, values must be entered for the MINLAT, MAXLAT, MINLON, and MAXLON parameters. AUTO is the default for this parameter.
The minimum latitude value to use in the mosaic.
The maximum latitude value to use in the mosaic.
The minimum longitude value to use in the mosaic.
The maximum longitude value to use in the mosaic.
If selected the application will track the mosaic origin. Once origin is tracked, the tracker cannot be turned off.
This option causes the application to fail if the input bandbin group does not match the mosaic bandbin group.
This option causes the application to fail if the input DEM shapemodel does not match the mosaic's' shapemodel.
This option causes High Saturation values (both Instrument and Representation) in the input image to be automatically copied to the mosaic irrespective of the priority
This option causes Low Saturation values (both Instrument and Representation) in the input image to be automatically copied to the mosaic irrespective of the priority
This option causes NULL values in the input image to be automatically copied to the mosaic irrespective of the priority