Imagery layers are web layers that raster data that represents a value in a matrix of equally sized cells, or pixels, arranged in rows, and columns. There are properties for each imagery layer that indicate the spatial resolution or cell size, the number of raster bands, and bit depth. These properties indicate ways that the imagery layer can be visualized, which features may be visible in the imagery layer, and the range of values available. Imagery layers can be created within ArcGIS Online or in ArcGIS Enterprise with the proper user type and privileges. Imagery layers can be created from many different input raster formats, but once created, share many common characteristics including:
- Pixel value access—the values for each cell or pixel can be accessed and identified within the map. These pixel values can appear in pop-ups to provide information about the specific location.
- Raster analysis ready—imagery layers can be used as input for raster analysis tools and raster functions.
- Modify symbology—the visualization of the imagery layer can be modified through modifying the raster band combination, image display properties, or applying processing templates.
- Maintains information about input images—imagery layers include metadata about the input imagery in a table.
- Supports multidimensional data—image format maintains access to multidimensional data, which allows for many dimensions and variables to be included in one imagery layer.
All of these imagery layers can be added to a map or web map, but how they function can determine which imagery layer is most appropriate. The characteristics of each type of imagery layer is described below. Consider which type of imagery format is best for you based on those characteristics.
* Hosted dynamic imagery layers cannot be shared with public (Everyone), but image services from ArcGIS Image Server can be shared as items in ArcGIS Online and shared publicly.
Dynamic imagery layers
Dynamic imagery layers and dynamic image services are published in ArcGIS Enterprise and are typically generated from a mosaic dataset or a collection of images. They are based on a single image or a collection of images that provide dynamic processing capabilities on the data for custom visualization in a map.
When a dynamic image service is referencing image files that are stored on and managed by ArcGIS Enterprise, it is considered a hosted imagery layer and appears in the portal as Imagery Layer (hosted). When a dynamic image service is referencing image files stored in a data store, it is no longer managed by ArcGIS Enterprise and appears in the portal as Imagery Layer. When you publish a dynamic image service from ArcGIS Pro, it is shared as a web imagery layer. Dynamic image services can be shared, queried, and analyzed in Map Viewer Classic, and processing and rendering are performed by the server.
An ArcGIS Image Server license is required to publish a dynamic image service to ArcGIS Enterprise.
Imagery type attributes
There are labels added to the item type column of the imagery layer when viewed in the Content page of your organization called Imagery type attributes. In addition to the type of layer that the item is, the Imagery type attribute provides more information about the imagery layer. For imagery layers, you can see the following attributes within parentheses:
- hosted—Indicates that the imagery layer is hosted in your organization.
- collection—Indicates that it is a dynamic imagery layer with an image collection.
- multidimensional—Indicates that the imagery layer is multidimensional and can be configured with the multidimensional settings in Map Viewer.
The Imagery type attribute can be used to locate particular imagery layers and provide additional information in the Content page about the imagery layer.
Imagery layer summary
Imagery layers provide the custom visualization and analysis options just like local raster datasets added to maps. Imagery layers shared through ArcGIS Enterprise or ArcGIS Online can be added to by accessing your portal in ArcGIS Pro. Once added to a web map, the imagery layers can be visualized, the raster properties modified, and used for raster analysis to suit your workflow.