Editing raster dataset footprints
Legacy:ArcGIS 10 is the last release of the stand-alone ArcGIS Image Server product. The image service definition (.ISDef) has been replaced by an improved geodatabase data model—the mosaic dataset—which can be published as an image service using the ArcGIS Server Image extension.
When a raster dataset is added to an image service definition, a footprint polygon is created. When the image service is published, each raster is clipped to its footprint. The footprint is not always the extent of each raster dataset, but it can be the extent of the valid raster data within the datasets. The footprint can be modified to exclude contents of a raster dataset, such as a border, an area of cloud cover, or a classified area.
When adding raster datasets, the footprints may not be correctly defined, because sufficient metadata about the extents may not be available. Also, adding or modifying processes that change the georeferencing of the raster data, such as orthorectification, may require the footprint to be recomputed.
Based on the raster dataset type, you will have to choose the most appropriate footprint recomputation method. There are various parameters that need to be specified based on the recomputing method you choose. Some recomputing methods are provided with options to specify the most commonly used parameter values that are used to redefine footprints for different types of imagery. These values can be modified through the Advanced tab.
All the footprint recomputation methods can be applied on every feature in the footprint or on a selected set.
There are several ways to edit the footprint polygons. You can use the editing tools within ArcMap to modify the shape of each footprint polygon, or you can use one of the following automatic methods provided on the Footprint layer context menu:
- Recompute Footprint By Geometry—Redefines the footprint polygon for each raster dataset by considering its warping once it is georeferenced or orthorectified. It is recommended that this operation be applied on raster datasets being orthorectified to remove slivers that may be generated alongside adjacent raster datasets due to terrain distortions.
- Recompute Footprint By Radiometry—Redefines the footprint polygon for each raster dataset based on a pixel value range. It is recommended that this operation be applied on rotated raster datasets with valid data in the center of the extent to remove the black (NoData) pixels that may be generated along the edges.
Learn about recomputing footprints to remove unwanted pixel data
- Recompute Footprint By Clipping To Boundary—Clips any footprint polygons extending outside the boundary polygon to within the boundary polygon. This is useful when the data in the image service extends beyond the desired extent of the image service.
Learn about clipping footprint polygons to the image service boundary
- Recompute Footprint By Shrinking—Reduces the size of the footprint polygons of each raster dataset so that edges are not used. In certain cases, using the very edge of a raster can cause artifacts in the service. This option enables the footprint to be reduced by a specified size. The edges of the footprint are moved toward the center of the footprint by the specified amount. The unit of size should be entered in the units of the data view's projection.
- Recompute Footprint By Related Geometry—Allows you to copy footprint polygon dimensions from an external table or layer. Before using this feature, the user should perform a join, the feature that allows the matching data from a layer or table (join table) to be added to the selected table or layer (target table).