Image service parameters

There are many standard parameters 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 parameters that can affect the speed of an image service, data that can be downloaded, querying, and many other options.

Some parameters are necessary when specific capabilities have been enabled. For example, if the Download capability is enabled, then the download parameters should be modified. This also applies to the Catalog, Editing, and Mensuration capabilities.

Default parameters to control the image data

The image service parameters are divided into several sections; each section is dependent 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 raster datasets or layers. Many mosaic dataset-related 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 parameters 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 effect.

Image parameters

The Image parameters affect the image that users connected to the image service will see.

Parameter	Description
Data Source	The location and name of the source dataset for the image service. Applicable to all inputs.
Maximum image size per request	The maximum number of pixel rows and columns 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.
Default resampling method	The resampling method used in the request. The methods include the following: Nearest Neighbor (recommended for discrete data) Bilinear Interpolation (recommended for continuous data) Cubic Convolution (recommended for continuous data) Majority (recommended for discrete data) Applicable to all inputs.
Allowed compression methods	The allowable compression methods for the image service. There are three possible compression types available: NONE JPEG LERC LZ77 A default JPEG Quality and LERC Tolerance can be set in the Configure Allow List dialog box. 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.
Return JPGPNG as JPG	When the user requests the image using the JPGPNG format, if there is transparency, a PNG is returned; otherwise a JPG is returned. The PNG is often much larger than the JPG and thus can take longer to transmit. If transparency is not necessary and you want to be sure the image service is always transmitted using a smaller image size, check this box. Applicable to all inputs.

Description of Image parameters

Cluster parameters

By default, every ArcGIS Server site has one cluster. If you have multiple server machines, you can configure them to operate in a cluster. Each cluster can be configured to run a dedicated set of services. The Choose the Cluster hosting the service parameter allows you to select the cluster in which your image service will operate.

Output Directory 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 the output directory. 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.

Description of Output Directory parameters

Parameters to control the image service catalog

The Catalog parameters only apply when publishing a mosaic dataset as an image service. These 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.

Mosaicking parameters

Parameter	Description
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.
Allowed mosaic methods	The allowable mosaic methods for the image service. The possible mosaic methods include the following: Closest To Center North-West Lock Raster By Attribute Closest To Nadir Closest To Viewpoint Seamline None Applicable to the mosaic dataset only.

Description of Mosaicking parameters

Catalog Property parameters

These parameters apply when the Catalog capability is checked.

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: Basic—Metadata of the raster Full—Metadata of the raster and the raster functions that are applied to the raster None—No metadata Applicable to the mosaic dataset only.
Allowed fields	This is a list of fields in the attribute table that are transmitted to the client. Uncheck the fields that you don't want a client to view or be able to use in a query. Applicable to the mosaic dataset only.

Description of Catalog Property parameters

Download parameters

When allowing download on an image service, be sure to check the Download capability on the Imaging property page. Also, in addition to the properties below, be sure to configure the output directories on the Parameters properties page.

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.
Manage downloaded directories	Allows you to map the physical directories where the images are located to a virtual directory where the image URLs will be mapped. When allowing download, 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. 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 the mosaic dataset only.
Maximum download size per request	This is the total number of megabytes that can be downloaded at one time. Applicable to the mosaic dataset only.

Description of Download parameters

Parameters to control image service content

Editing parameters

If an image service is created from a mosaic dataset, you can configure the image service to act as a repository for your clients by allowing clients to add their raster data to the mosaic dataset. Once added, the same clients may edit the properties of or remove the data they added.

These parameters apply when the Editing capability is checked.

Editing cannot be used when serving a referenced mosaic dataset.

Parameter	Description
Manage dynamic image workspaces	Directory location, accessible from the server and mosaic dataset, where the raster data will be uploaded and stored. This must be set, otherwise, the editing operations cannot be used by the service. Applicable to the mosaic dataset only.
Editor Info	Choose to add a realm to the user name when applying edits so they can be tracked. When you access a secured image service, ArcGIS for Server remembers the user's name and their edits. ArcGIS for Server will also append any realm that has been configured on the image service. Applicable to the mosaic dataset only (with editor tracking enabled on the mosaic dataset).
Operations allowed on items added by other users	Update—Allows clients to update the properties of the raster dataset they added to the image service. Delete—Allows clients to remove a raster item from image service. Applicable to the mosaic dataset only (with editor tracking enabled on the mosaic dataset).
Allowed types for add	Choose one or more raster types from which clients can pick when adding raster data to an image service. Applicable to the mosaic dataset only.
Manage custom types	If you need clients to add data not defined by the basic raster types, you can select one or more raster type files (.art). Raster type files can be created and edited in the Add Rasters To Mosaic Dataset tool by opening the raster type's properties and saving the file. Applicable to the mosaic dataset only.

Description of Editing parameters

Parameters to control on-the-fly processing

Function parameters

Functions allow the image service data to be processing by the server to provide specific products to the client. Some functions are exposed directly, such as Hillshade and Slope; however, all the functions that can be applied to the raster data in ArcGIS for Desktop can be exposed to clients using raster function templates. The following parameters control the on-the-fly, server-side processing using functions that will be exposed to clients.

Parameter	Description
Allow client specified rendering rules	If checked, then clients can access and control the server-side rendering and processing. If unchecked, then the client cannot access and request any server-side rendering. Applicable to all inputs.
Convert Colormap to RGB	If your raster dataset has a colormap you can choose to publish it as an RGB image, thereby applying the colormap to the image. This will impact the pixel values since the values will be changed from a single value and associated colormap to a 3-band pixel value. To retain the colormap and allow a user to query the pixel based on its colormap, you should not select this option. This applies to raster datasets with a colormap, or when using a raster dataset layer or mosaic dataset using the Colormap function. Applicable to all inputs.
Manage raster function templates	You can provide one or more function chains that can be used to process the data in the image service. When applied, these functions are applied on the server and the result is transmitted to the user or application. These function chains are created in the Raster Function Template Editor and saved as .rft.xml files, created in ArcMap, that can be applied to the image service. These are provided to allow web applications to perform various on-the-fly processing on the data in the image service. You can choose a default function chain that is applied whenever the image service is used. This is especially useful when using an image service with data that looks better when it is stretched. ArcMap will apply a stretch, but web applications typically cannot; therefore, you can be sure it will always look the way you want if you define the stretch using a function chain. Learn more about server-side processing Applicable to all inputs.

Description of Function parameters

Parameters to control image mensuration

Mensuration parameters

ArcGIS provides a set of tools for image mensuration, including tools to measure point, distance, area, and height from an image. You can choose whether you want the image service to participate in ArcGIS's image mensuration.

Applicable to all inputs.

Parameter	Description
Allowed mensuration methods	These allowed methods are derived from the source's mensuration capabilities, listed as part of the dataset's properties. They determine the mensuration tools that can be used with the image service. Basic—The Distance, Area, Point Location, and Centroid Location mensuration tool can be used. These tools will be available with all the other options, except None. 3D—The measurements made using the tools available with the Basic option can be modified using a DEM. Height—The sensor model exists for datasets within the mosaic dataset; therefore, the Height: Using Base To Top mensuration tool can be used. Shadow—The sensor model and sun angle information exists for datasets within the mosaic dataset; therefore, the Height: Using Base To Top, Height: Using Base To Top Shadow, and Height: Using Top To Top Shadow mensuration tools can be used. None—The user will not be able to use the mensuration tools in ArcGIS with this dataset. Applicable to all inputs.
Elevation Source	If there is a preferred and available elevation source that should be used when mensurating, you can point to it here. This will allow the user to make measurements in 3D. Valid elevation sources include raster datasets, image service SOAP URL's, and image service layers. If the elevation image service requires authentication, then you should use an image service layer. Applicable to all inputs.

Description of Mensuration parameters