Imagery and raster data can be shared as an image service using ArcGIS for Server. An image service provides access to raster data through a web service. You can also share the data as part of a document, such as a map or globe document, or as part of other services, such as a geodata service.
What data can be published as an image service?
The source for the image service can be a raster dataset, a mosaic dataset, or a layer file referencing a raster dataset or mosaic dataset. Sharing raster datasets or raster layers that define on-the-fly processing, such as symbology or raster functions, is a core capability of image services and does not require an extension. The ArcGIS Image extension is required to share a mosaic dataset, a raster layer containing a mosaic function, or a map or globe document containing a mosaic dataset.
Lidar data can also be shared as an image service. You can add terrain datasets, LAS datasets, or LAS files to a mosaic dataset, then share the mosaic dataset as an image service. This makes the lidar data available as a raster, not points, but the source files can be accessed if you enable the download capability on the image service. Learn more.
Compiled image service definition files (.ISCDef), created using ArcGIS Image Server, are no longer published using ArcGIS for Server. You should convert the .ISDef to a mosaic dataset.
The ArcGIS Image extension is a license added to ArcGIS for Server
to extend the capability of serving raster data. Specifically, it
allows you to serve a mosaic dataset, or a raster layer containing a
mosaic function. Therefore, if you are serving an image service,
the following are true:
the extension, you can serve a raster dataset or raster dataset
- With the
extension, you can serve a mosaic dataset or mosaic dataset
This extension adds the
- Serve collections of imagery or lidar data as image services
Dynamically create and serve mosaics from the original
imagery, without the need to precompute the mosaics.
multiple views using the original imagery.
the catalogs of imagery that make up the mosaic dataset.
overlapping imagery, perform on-the-fly image processing, and
explore temporal changes using the advanced image serving
capabilities of this extension.
Image service capabilities
When you publish an image service, you should consider how clients will be connecting to the image service. An image service is always published with imaging capabilities allowing clients to connect it using an ArcGIS for Server connection or via REST. However, you can also choose to publish an image service with the Open Geospatial Consortium, Inc. (OGC) Web Map Service (WMS) or Web Coverage Service (WCS) capabilities. By adding additional capabilities you allow clients to access your image service in an expanded variety of applications and devices.
There are many operations that can be performed with an image service—especially when publishing a mosaic dataset. These include:
- Image—Allows the image to be displayed.
- Catalog—Allows the client to open the table of a published mosaic dataset.
- Download—Allows rasters to be downloaded from a published mosaic dataset.
- Edit—Allows clients to add, delete, or update raster data to a published mosaic dataset.
- Mensuration—Allows the client to use this image service with the mensuration tools in ArcGIS.
- Metadata—Allows the client to see metadata information for each raster when publishing a mosaic dataset.
- Pixels—Allows the API developer to access the pixel blocks of the individual rasters when publishing a mosaic dataset.
Preparing image services
There are many things to consider when you are preparing to create an image service, because not all raster data is served in an equal manner; it depends on the capabilities and the operations within them you choose. There are several common questions to ask, such as:
- Is there one raster dataset or many raster datasets?
- Is the raster data for viewing as a base image or as input for analysis?
- Does the data have multiple bands or need to be enhanced?
- Is any processing required?
To learn about each of these, see Preparing image services.
You also need to make sure the data is accessible to the server. If not, it will be moved to the server when the image service is published.
Caching image data
Caching is only required when you must create the fastest possible service containing image data. Generally, the pyramids generated for raster datasets or the overviews generated for mosaic datasets result in image data being served at an acceptable rate. However, if you know that a particular image or area of interest will be repeatedly visited, you may want to generate a cache.
You can cache an image service or cache a map service or globe service containing raster data or an image service. Unless there is a need to cache all the contents of a map or globe service, it is generally recommended that you cache the vector data and not the image data, especially when they contain an image service.Learn about caching image services
Using an image service
You can access an image service the same way you would any other service—by first connecting to the GIS server, then choosing the image service that is available. As mentioned above, how you use the image service depends on the source data. Therefore, a published raster dataset can be used like a raster; however, a published mosaic dataset can be used like a single raster (image) or catalog. See the following to learn about using an image service: