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—for dynamic imagery layers created as an image collection, the input image metadata is maintained 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.
When you create an imagery layer in ArcGIS Online you are hosting an imagery layer that can be shared with others online. These layers will have the (hosted) label in the layer item name when viewed in the Contents group in ArcGIS Online. Imagery layers without the (hosted) label are referencing other hosted imagery layers in ArcGIS Online. Duplicating and saving imagery layers can create items within your organization that reference the imagery layers. For more information on managing your hosted imagery layers, please see Manage hosted imagery layers.
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.
Imagery layers
When imagery layers are created, they are considered to be hosted in ArcGIS Online, which allows you to use the imagery layers online as either a dynamic imagery layer or a tiled imagery layer. Both imagery layers can be used for similar purposes, but there are some differences between the two types.
Dynamic imagery layers
Dynamic imagery layers and dynamic image services are published in ArcGIS Enterprise or published from ArcGIS Pro to an ArcGIS Image Server site. Dynamic imagery layers can also be hosted in ArcGIS Online by users with a Creator, Professional, or Professional Plus user type with the Publish Hosted Dynamic Imagery privilege. 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 the publisher shares the dynamic imagery layer or dynamic image services with you, you can add it to Map Viewer or Map Viewer Classic, where you can query and analyze it.
Note:
Dynamic imagery layers can only be shared within your ArcGIS Online organization and cannot be shared with everyone.
Tiled imagery layers
Tiled imagery layers are published and hosted in ArcGIS Online. These layers are image services generated from one or more image files. If a tiled imagery layer is created using multiple images, the images are mosaicked together into a single image. Source image and raster files are converted to Cloud Raster Format (CRF) when uploaded to your ArcGIS Online organization. You can share, query, and analyze hosted tiled imagery layers in Map Viewer Classic, and access them as static image tiles with client-side processing and rendering.
If WMTS is enabled, the endpoint link will be under the service's REST page. For more information about how to enable WMTS, review the documentation on the requirements to enable it here.
A Creator, Professional, or Professional Plus user type with the Publish tiled imagery layers privilege is required to publish hosted tiled imagery layers to ArcGIS Online.
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.
Note:
Tiled imagery layers cannot have the collection attribute. Only dynamic imagery layers can have the collection attribute.
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.