These directives are used when reading a mosaic dataset using the raster dataset reader.
MOSAIC_METHOD
A Mosaic Dataset is a collection of rasters that can be combined to produce a single raster image for viewing or analysis. This directive provides options to combine the rasters to produce the desired result.
The following values are supported:
- None – Rasters will be ordered in the order they appear in the mosaic dataset catalog table
- By Attribute – Rasters will be ordered by how close the value of the attribute given by MOSAIC_ORDER_FIELD is to the value supplied in MOSAIC_ORDER_VALUE.
- Closest to Center – Rasters are ordered by how close they are to the center of the combined image.
- Lock Raster – Only those rasters given in Lock Raster ID will be combined in the order listed
- North-west – Rasters are ordered by how close they are to the north-west of the combined image.
- Seamline – Rasters will be combined using the existing seamlines.
Required/Optional
Optional
Values
None | By Attribute | Closest to Center | Lock Raster | North-west (default) | Seamline
Workbench Parameter
Mosaic Method
MOSAIC_ORDER_FIELD
When the value of MOSAIC_METHOD is set to ‘By Attribute’ then this directive specifies which field in the mosaic dataset’s attribute table will be used to compare values.
Required/Optional
Required when MOSAIC_METHOD is set to ‘By Attribute’
Workbench Parameter
Order Field
MOSAIC_ORDER_BASE_VALUE
When the value of MOSAIC_METHOD is set to ‘By Attribute’ then rasters will be ordered by how close the value of the field given by MOSAIC_ORDER_FIELD is to the value given in this directive.
Required/Optional
Optional
Values
Any real number (default 0)
Workbench Parameter
Order Base Value
MOSAIC_LOCK_RASTER_ID
This directive lists the ObjectIDs as a comma-separated list that will be used to give the order of the rasters when the value of MOSAIC_METHOD is set to ‘Lock Raster’.
Required/Optional
Required when MOSAIC_METHOD is set to ‘Lock Raster’
Values
Comma-separated list of Raster ObjectIDs
Workbench Parameter
Lock Raster ID
MOSAIC_ORDER
Gives the option to reverse the order the rasters will be combined.
- Ascending – Those ordered first will be placed on top
- Descending – Those ordered first will be placed on the bottom
Required/Optional
Optional
Values
Ascending (default) | Descending
Workbench Parameter
Lock Raster ID
MOSAIC_OPERATOR
It is possible for more than one raster to overlap in any given area. The MOSAIC_OPERATOR specifies how the cells in the overlapping area are combined.
- First – The cell from the first raster is chosen.
- Last – The cell from the last raster is chosen.
- Min – The cell with the smallest value is chosen.
- Max – The cell with the largest value is chosen.
- Mean – The average of all the cells is chosen.
- Blend – Overlapping cells will blended together based on a weight-based algorithm that uses the distance of the cells to the edge within the overlapping area.
Required/Optional
Optional
Values
First (default) | Last | Min | Max | Mean |Blend
Workbench Parameter
Mosaic Operator
NODATA_HANDLING_FOR_MANAGED_RASTERS
Managed rasters, rasters stored within the Geodatabase, represent nodata as a bit mask on each band. This directive specifies how to handle these nodata bit masks.
- None – Nodata bit masks will be ignored
- Single Alpha Band – Nodata bit masks for each band are merged into a single additional alpha band named geodb_nodata.
If merged into a single alpha band, then the alpha band will contain a value of zero (nodata) at a given cell if and only if the corresponding cell of all the other bands is nodata.
This directive only affects managed rasters. Unmanaged rasters, rasters stored in files outside the Geodatabase, have nodata represented as a nodata value per band and do not have nodata bitmasks.
If this directive is not supplied, then the handling will default to None.
Required/Optional
Optional
Values
None | Single Alpha Band (default)
Workbench Parameter
Nodata Handling for Managed Rasters