Publishing image services
There are many standard properties for an image service that are set for most ArcGIS Server services. These include the pooling options and several others. However, due to the nature of raster and image data, there are many specific properties that can affect the speed of an image service, data that can be downloaded, querying, and many other options.
Image service parameters to control the image data
The image service parameters are divided into four sections: Image, Catalog, Download, and Output. These parameters are not applicable to all image services and depend on the input for the image service. Most of these parameters are specific to image services serving mosaic datasets and only a few affect an image service created from a raster dataset. Most of these parameters are set when you create the mosaic dataset, but some can be altered by the server administrator. However, the server administrator will not be able to exceed the maximums you have set in the mosaic dataset properties. For example, if you limit the allowed mosaic methods to only three of the methods, the administrator will not be able to add a fourth method. Or, if you set the maximum number of downloadable items, they can reduce the number but not increase this number.
If you change the properties of the mosaic dataset to exceed or limit a value, such as the maximum size of requests, you need to republish it as an image service for the server to read the modified values. If you only restart the image service, the changed properties in the mosaic dataset will not be picked up. Whereas, if the server administrator changes the properties of the image service they only need to restart the image service for the changes to take affect.
Image parameters
The Image parameters affect the image that users connected to the image service will see.
|
Parameter |
Description |
|---|---|
|
Maximum image size per request |
The maximum number of pixel rows and rows that the server allows in a client request. If the client’s request exceeds this value, then none of the pixels will be returned. Applicable to all inputs. |
|
Maximum number of rasters per mosaic |
The maximum number of rasters that can be mosaicked per request. This will prevent the server from performing the mosaic operation if too many rasters are included in the request. If the client's request exceeds this value, then none of the pixels will be returned. It is recommended that overviews can be built so that the client will not end up with a blank screen. Applicable to the mosaic dataset only. |
|
Default resampling method |
The resampling method used in the request. The methods include the following:
Applicable to all inputs. |
|
Allowed compression methods |
The allowable compression methods for the image service. There are three possible compression types available:
The client can then choose which allowable compression method to use for transmission. This can be set in the Display tab in the Layer Properties dialog box. Applicable to all inputs. |
|
Default compression quality |
The compression quality used for the image service. It is only valid with JPEG compression. Applicable to all inputs. |
|
Allowed mosaic methods |
The allowable mosaic methods for the image service. The possible mosaic methods include the following:
The default method will be listed first. The client can then choose which allowable mosaic method to use. This can be set in the Mosaic tab in the Layer Properties dialog box. Applicable to the mosaic dataset only. |
Catalog parameters
The Catalog parameters control or limit the access users have to metadata and the catalog fields, as well as limit the requests for records from the mosaic dataset tables. These parameters can affect the load on the server. The more you allow a user to view and query, the greater the draw on the server.
|
Parameter |
Description |
|---|---|
|
Maximum number of records returned per request |
The limit on the number of records transmitted per transaction. If the user’s request exceeds this value, then the image returned uses the maximum allowed rasters. Applicable to the mosaic dataset only. |
|
Raster metadata level |
The metadata that will be transmitted to the client:
Applicable to the mosaic dataset only. |
|
Allowed fields |
This is a list of fields in the table that are transmitted to the client. Applicable to the mosaic dataset only. |
Download parameters
These parameters affect the load on the server and the access users have to the source images.
|
Parameter |
Description |
|---|---|
|
Maximum number of items downloadable per request |
The maximum number of rasters that the user can download at one time. Applicable to the mosaic dataset only.  Note:Source files stored using the GRID raster format cannot be downloaded. |
|
Directories |
The list of physical directories where the images to be downloaded are located. When publishing a mosaic dataset that will be used to call the REST download operation, it is critical that the service uses a directory that points to the source rasters of the mosaic dataset. This prevents a huge performance bottleneck that would otherwise occur as the service copies files from the mosaic dataset source directory to the server output directory. Applicable to the mosaic dataset only. |
|
Virtual Directory |
The virtual directory where the image URLs will be mapped. Applicable to the mosaic dataset only. |
Output parameters
|
Parameter |
Description |
|---|---|
|
Directory |
Choose the output directory where you want the server to create temporary files. If you don't specify the output directory, the ArcGIS server will only return images as MIME data. By specifying an output directory (that has an associated virtual directory), the returned images will also be accessible via a URL address. Use the Server Properties dialog box to create output directory. Applicable to all inputs. |
|
Virtual Directory |
The virtual directory provides Web applications' access to files created by the ArcGIS server via a URL address. The virtual directory should point to the same disk location as the output directory. You must create the virtual directory in your Web server and link it to the physical directory on disk. Refer to your Web server documentation on how to create virtual directories. Applicable to all inputs. |
|
Supported Image Return Type |
Shows if the images generated by the ArcGIS server will be returned as MIME data only or both MIME and URL. To access images generated by the ArcGIS server over the Internet, you must specify a server directory with an associated virtual directory (pointing to the same physical directory) for output images. Applicable to all inputs. |
Options for publishing depending on your setup
Your options for publishing image services will vary depending on which software you have:
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I have ArcGIS Server only.
You can only publish raster datasets and layer files that reference raster datasets. You can use either ArcCatalog or Manager to publish the service. Follow the steps in Publishing a GIS resource to the server. When prompted for the resource, browse to the raster dataset or layer file that you want to publish.
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I have ArcGIS Server and the Image extension.
You can publish raster datasets, mosaic datasets, or layer files that reference raster datasets or mosaic datasets. You can use either ArcCatalog or Manager to publish the service. Follow the steps in Publishing a GIS resource to the server. When prompted for the resource, browse to the raster dataset, mosaic dataset, or layer file that you want to publish.
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...and ArcGIS Server is registered with an ArcGIS Image Server.
In addition to raster datasets and mosaic datasets, you can publish compiled image service definitions. You can use either ArcCatalog or Manager to publish the service. Follow the steps in Publishing a GIS resource to the server. When prompted for the resource, browse to the raster dataset, mosaic dataset, layer file, or compiled image service definition that you want to publish.
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...and ArcGIS Server is registered with a JPIP Server.
You can publish JPEG 2000 or NITF (with JPEG 2000 compression) files using the JPIP streaming capability when ArcGIS Server is configured with a JPIP Server from ITTVIS. You can use either ArcCatalog or Manager to publish the service. Follow the steps in Registering JPIP Server with ArcGIS Server to register a JPIP Server with ArcGIS Server.
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