Descriptions of the image service definition properties

The properties of an image service definition include information required to create and publish one using ArcGIS Image Server. The information is the name of the image service, location of the raster table, processes to be applied to the image service, metadata, and so on. There are a large number of image service properties. When creating a new image service definition, default or blank properties are defined. You can view and modify the properties on the Image Service Properties dialog box. To open the Image Service Properties dialog box, you can either click the Image Service Properties button 影像服务属性 on the Image Service Definition Editor toolbar or right-click the image service definition group layer in the table of contents and click Properties.

On the Image Service Properties dialog box, the properties are organized into nine groups:

ServicePropertiesInformation node

Information

This section of the Image Service Properties dialog box enables you to store author and historical information of the service. This information is not sent out to client applications. A section is provided to store comments to keep track of changes made by the author.

Image service definition information

Field

Description

Version

Version of image service definition (.ISDef) format. This field is defined by the Service Editor.

Author

Author of the image service definition.

Organization

Name of the organization that created the image service definition.

Last updated

Date and time when the image service definition was last updated. This field is updated by the Service Editor.

Service def. creation date

Date when the image service definition was created.

Service def. creation time

Time when the image service definition was created.

Comments

Comments for reference by the author.

Edit history

History of updates made to the image service definition.

Image service definition information

A Status button enables you to check the status of the image service definition by providing the status identification and status message. The status identification can be a positive, negative, or 0 value. Positive values indicate a warning; negative values indicate an error. A value of 0 indicates that the operation was successful.

Service Definition

Key image service parameters are critical to the image service definition. These parameters determine how an image service definition is specified in terms of the location of files, spatial reference system, pixel type definition, number of bands, and so on.

Definition of service parameters

Field

Description

Service name

Default name of the image service definition that is displayed when accessed from the ArcGIS Image Server client. The service name can include a backslash (\) to form a folder structure enabling services to be logically grouped and displayed to the client. For example, Germany\Amberg is a valid name. When publishing, this name is given by default, but it can be changed.

Spatial reference system

Defines the spatial reference system used for the image service definition. This is used for all internal searches and derived tiles. The spatial reference should be chosen such that no coordinate system boundaries exist within the extents of the required image service definition.

Home folder

All path references to raster process definition files, service (footprint) table, and seamline table are relative to this folder. If undefined, it defaults to the folder containing the image service definition. By default, it is blank.

Service table

Full path to the service table that lists raster datasets to be served with footprints. Specify the full path to a shapefile that should be used as the service table for this image service definition. The spatial reference of these footprints must be that of the image service definition. If undefined, the default is <home folder>.

Raster source field

Name of the field in the service table that contains the reference to the raster dataset. This feature allows the same table to point to different raster sources depending on the setting in the image service definition. This is useful in cases where the service table needs to be reused for slightly different sets of rasters. It is typically used when creating two image service definitions that use the same service table. By default, it is left blank, which is equivalent to the RasterSrc field in the service table.

Seamline source

An external shapefile that defines the seamlines for corresponding raster datasets around which rasters are to be mosaicked. Specify the full path to a shapefile that contains the seamline shapes for this image service definition. If undefined, the default is <home folder>.

Boundary source

An external shapefile that defines the boundary for the corresponding image service definition. Specify the full path to a shapefile that contains the boundary shape for this image service definition. If it contains more than one shape, the first shape is used as the boundary shape. If undefined, the default is <homefolder>\Boundary.shp. The value of <homefolder> is defined above. By default, it is blank.

Max. rasters displayed

Prevents the server from mosaicking an unreasonably large number of rasters if, for example, the client zooms in to an overview scale in an unoptimized image service definition that has no overview tiles generated. The default is 20.

Transparency

Defines whether NoData values have to be treated as transparent. Specifying Unchanged means the transparency for each raster is defined in the corresponding raster process definition. This can be used to override the values. In most cases, NoData values can be cropped using footprints, which are more efficient than pixel-based transparency.

Process weight

Weight given to the image service definition that defines the relative amount of processing required for each request. It is used to tune the load balancing. Services that contain more processing should be given higher values relative to services with little processing to help optimize load balancing when services are loaded on multiple service providers.

Verbose reporting

If checked, more detailed log files are created by the service provider.

Definition of service parameters
Definition of pixel prior to service process

Field

Description

Number of bands

Number of bands in the image service definition. Defines the number of bands that each raster should have when mosaicked together prior to applying the service process. The output of all added raster datasets or raster process definitions should contain this number of bands.

Pixel type

Input pixel type of the image service definition. This is the pixel type that different rasters should be when they are mosaicked together before applying the service process. Each raster dataset or raster process definition added to this service must be of this pixel type.

Bit depth

Specifies the number of bits of the image service definition when rasters are mosaicked before applying the service process. Bit depth defines the size of the histogram and radiometric transformations to be used. For example, a 16-bit-depth raster might use only 12 bits compared to the available 16 bits. This value affects the histogram and radiometric transformations used.

Color space

Defines the relationship between the bands of the pixel. This is required primarily to enable compression.

Definition of pixel prior to service process

Service Processes

Defines the chain of processes that can be applied to the image service definition. These processes are applied to the data after all rasters requested by the client are mosaicked together. See An overview of image service definition processes for a detailed description of each process. Some examples of these processes are Stretching, Convolution Filter (sharpening), NDVI, or Visualize Elevation. For example, a service can define elevation models in such a way that the pixel type is Elevation. As a service process, a Visualize Elevation process can be applied in such a way that the output image sent to the client would be a red, green, and blue (RGB) image. Defining the service can change the pixel type and number of bands of the output.

Output Definition

The output definition of an image service definition describes the output to the client after the service processes have been applied.

Properties of Output Definition

Definition of output imagery

Field

Description

Number of bands

Output number of bands in the image service definition. This is the number of bands of the image that is output or transmitted by the image service definition.

Pixel type

Output pixel type of the image service definition. This is the pixel type of the image that is output or transmitted by the image service definition.

Bit depth

Output bit depth of the image service definition. This is the bit depth of the image that is output or transmitted by the image service definition.

Color space

Defines the relationship between bands of the pixel. This is required primarily to activate compression.

Minimum pixel size

The minimum pixel size in the service below which requests are not handled. It is defined in meters irrespective of spatial reference system. The default of this parameter is 0, but it can be set to a larger number to limit the resolution at which a client can access imagery. If a request is made below this resolution, the request fails and the out-of-range image is returned (see the Client Interface Control description).

Maximum pixel size

The maximum pixel size in the service above which requests are not handled. The default value is a large number, unlike the minimum pixel size default. If a request is made above this resolution, the request fails and the out-of-range image is returned (see the Client Interface Control description).

Base pixel size

The base pixel size to be used for derived images, defined in meters. Service overviews are defined at pixel sizes that are a factor of this value. If this is undefined, the value is taken as the smallest low pixel size from all rasters.

Definition of output imagery
Bounding coordinates in geographic coordinates (WGS1984)

Field

Description

X minimum

Minimum x-value of the envelope. This is computed during the build and compilation of the service.

X maximum

Maximum x-value of the envelope. This is computed during the build and compilation of the service.

Y minimum

Minimum y-value of the envelope. This is computed during the build and compilation of the service.

Y maximum

Maximum y-value of the envelope. This is computed during the build and compilation of the service.

Z minimum

Minimum z-value of the envelope. This is computed during the build and compilation of the service.

Z maximum

Maximum z-value of the envelope. This is computed during the build and compilation of the service.

Bounding coordinates in geographic coordinates (WGS1984)

Metadata

Metadata service parameters contain information about the service that is provided to client applications. This metadata can provide an overview of the origin of data, processes applied, and so on. Most of the parameters are available to clients before opening the service. They are also visible to the client while reviewing service metadata from the client properties.

Service metadata

Subject

Description

Title

Title given to the image service definition.

Edition

Edition of the service.

Identifier

Unique ID of the service and version number.

Geographic region

Description of the geographic region, for example, town, state, country. It assists clients when selecting a service.

Pixel unit

Describes pixel units of imagery, for example, true color, false color, NDVI legend, radiance, elevation in meters, and elevation in feet.

Pixel source

Source from which the pixel values are obtained. This is generally the sensor type or the original source, such as aerial photography, scanned map, or Landsat.

Processing summary

Summary of the processing that is applied by the image service definition on raw imagery.

Abstract

Abstract of the service.

Purpose

Purpose of the service.

Originator

Originator of the service.

Publisher

Publisher of the service.

Rights

Owners of rights to the data and service.

Contact organization

Contact organization.

Contact person

Person to contact for specific information about the image service definition.

Time period begin

Date of the first image in the service.

Time period end

Date of the last image in the service.

Service creation date

Date when the image service definition was last compiled.

Service creation time

Time when the image service definition was last compiled.

Service metadata

Client Interface Control

The Client Interface Control section provides control of service properties a client can access or modify. Although there are a number of properties that can be changed in a service, in some applications, it is advantageous to restrict this control. The properties of this form define these restrictions, change the Client Properties interface control displayed to the end users, and restrict the specified feature.

Client interface control

Field

Description

Maximum columns

Maximum number of columns of pixels. If 0, no limit is placed. The default value is 15000 pixels.

Maximum rows

Maximum number of rows of pixels allowed in a single mosaic request. The default value is 4100 pixels.

Allowed mosaic methods

An image returned to the client by mosaicking a number of different rasters. The mosaic method defines the order of the rasters and method by which they are fused.

  • Closest to Center—Enables rasters to be sorted based on a default order where rasters that have their centers closest to the view center are placed on top.
  • Closest to Nadir—Enables rasters to be sorted by the distance between the nadir position and view center. This is similar to the Closest to Center setting; however, it uses the nadir point to a raster, which may be different from the center, especially for oblique imagery.
  • Closest to Viewpoint—Orders rasters based on a user-defined location and nadir location for the rasters using the Viewpoint tool.
  • By Attribute—Orders rasters based on a defined metadata attribute and its difference from a base value.
  • Most Northwest—Orders rasters in a view-independent way where rasters with their centers most northwest are displayed on top.
  • Seamline—Cuts the raster using the predefined seamline shape for each raster using optional feathering along the seams.
  • Lock Raster—Enables a user to lock the display of single or multiple rasters based on an ID or name.
You can select multiple mosaic methods using the SHIFT and CTRL keys. By default, the Closest to Center and Lock Raster methods are selected.

Allowed client side processes

A list of processes that a client application can select to have applied by the server. Multiple processes can be selected. (This is not used by any of the present client applications but can be used by a developer-created client.) The Grayscale, Visualize Elevation, Stretching, and Extract Bands processes are not listed here, since they are allowed by default.

Order fields

List of tile order fields that a client can select. Multiple fields can be selected. The available list is created from all the fields in the service table that are of type metadata and are numeric (for example, the values can represent dates or cloud cover percentages). These fields are displayed in the service properties that can be viewed by the client.

Transmit process metadata

If checked, the metadata about the processing, including the process parameters for each raster, can be transmitted to the client. By default, this is unchecked.

Transmit raster footprints

If checked, the footprint of each raster dataset that forms a mosaic can be sent to the client application. By default, this is checked.

Transmit raster info

If checked, information (including name of source file) about the raster datasets that form the mosaic can be sent to the client application. By default, this is checked.

Transmit raster metadata

If checked, the metadata stored in the raster process definition of each raster dataset that forms the mosaic can be transmitted to the client. By default, this is unchecked.

Client interface control

Default Client Properties

When a client application accesses imagery from ArcGIS Image Server, properties of the service can be changed to suit the client's requirements. When a client first connects to the server, the service is defined with default properties. The properties a client can access and change are defined in the Client Interface Control.

Default properties for a client connection

Field

Description

Spatial reference system

Defines the default spatial reference system the images are in for the client application. Each client makes a request to the server for an image based on a rectangular window in the required spatial reference (the rectangular window is generally defined by the display window in which the image service is viewed). Some client applications can define or redefine the required spatial reference. The value defined here is used by default, or the client application overrides it. By default, it is the same as the image service definition's spatial reference system.

Sampling method

Defines the default sampling method of raster pixels, which are sampled to match the resolution of the client request. Depending on the application, the sampling method can be changed. More accurate radiometry values are obtained using nearest neighbor sampling. This is generally faster but can result in jagged edges of features. Bilinear interpolation provides smoother images but can result in some smoothing of the image. Cubic convolution is geometrically more accurate but slightly slower than bilinear interpolation.

Mosaic method

Defines the default mosaic method for the image returned to the client. The mosaic method defines the order of the rasters and method by which they are fused.

  • Closest to Center—Sorts based on a default order where rasters that have their centers closest to the view center are placed on top.
  • Closest to Nadir—Sorts by the distance between the nadir position and view center. This is similar to the Closest to Center setting; however, it uses the nadir point to a raster, which may be different from the center, especially for oblique imagery.
  • Closest to Viewpoint—Orders rasters based on a user-defined location and nadir location for the rasters using the Viewpoint tool.
  • By Attribute—Orders rasters based on a defined metadata attribute and its difference from a base value.
  • Most Northwest—Orders rasters in a view-independent way where rasters with their centers most northwest are displayed on top.
  • Seamline—Cuts the raster using the predefined seamline shape for each raster using optional feathering along the seams.
  • Lock Raster—Enables a user to lock the display of single or multiple rasters based on an ID or name.

Average image spacing X

The average (mode) spacing between rasters in the x direction. It is computed during the build process, when computing the output pixel properties. This is used by the client to control the shift in the apparent viewpoint center when using the Viewpoint mosaic method. The client interface will change the apparent view center by this amount when users indicate they want to see the raster from one side.

Average image spacing Y

The average (mode) spacing between rasters in the y direction. It is computed during the build process, when computing the output pixel properties. This is used by the client to control the shift in the apparent viewpoint center. The client interface will change the apparent view center by this amount when users indicate they want to see the raster from one side.

Viewpoint default shift X

If in viewpoint mode and the viewpoint coordinate is not defined, the viewpoint is set as the view center shifted by this amount. This can be used to shift the default view to give priority to rasters from a specified direction. For example, view buildings primarily from the southwest by giving a negative value. A value of 0 would give the same results as Closest to Nadir.

Viewpoint default shift Y

If in viewpoint mode and a viewpoint coordinate is not defined, the viewpoint is set as the view center shifted by this amount. This can be used to shift the default view to give priority to rasters from the specified direction. For example, view buildings primarily from the southwest by giving a negative value. A value of 0 would give the same results as Closest to Nadir.

Order field

The default field to use to order rasters when the mosaic method is By Attribute. The list of fields is defined as those in the service table that are of type metadata and are numeric (for example, the values can represent dates or cloud cover percentages).

Order base value

The images are sorted based on the difference between this value and attribute value in the specified field.

Lock raster ID

Raster ID or raster name to which the service should be locked, such that only the specified rasters are displayed. If left blank (undefined), it will be similar to the system default. Multiple IDs can be defined as a semicolon-delimited list.

Compression method

Defines the method of compression to transmit the mosaicked raster data from the server to the client. If accessing the image services over a LAN, large data volumes do not cause a problem. However, when working over slower connections on the Internet, it would be better to apply a compression to the imagery before transmission. This compression reduces the size of transmitted imagery but puts an additional load on the service provider to compress the data first.

  • Uncompressed—Results in no compression being applied to the imagery, providing the highest quality but resulting in the maximum data transfer across the network.
  • JPEG—An efficient compression method that can often compress imagery by about three to eight times with little degradation in the image quality.
  • JPEG 2000—Wavelet-based compression, which provides high compression ratios (8–15) with little degradation in the image quality but only when the size of the image transmitted is large. For small screen-sized requests, JPEG is generally better. JPEG 2000 also puts a heavier load on the service provider.
  • LZ77—An efficient, lossless compression method that is often used for imagery with similar pixels, such as scanned maps or classification results.

Compression quality

Defines the quality of compression using a percentage value. The value of 100 percent is the best quality; however, it affects the total size the least. A value of 1 percent would result in the smallest transmission size. Generally, when using JPEG, 80 percent compression is a good value with minimal artifacts.

Background color

Background color of the image service. Used by ArcGIS Image Server and all other components specified in the image service definition when no imagery is available. Clicking the colored square beside the text box allows you to interactively choose a color, which results in a number entered into the text box.

Default properties for a client connection

Service Defaults

This section defines default values used by the Build and Optimize features of Image Service Editor. Changing the values provides the required defaults.

Default values used by Image Service Editor

Build parameters

Field

Description

Min. pixel size range factor

A factor for computing the pixel size range to be used for an image. If an overlapping image is within this factor in pixel size, it is assumed that images should overlap and the range to be used will not be limited. If an image fully overlaps another and has a pixel size larger by this factor (and less than the Max. pixel size range factor value), the range of the raster will be limited to the pixel size of the overlapping image. By default, this is 1.9.

Max. pixel size range factor

A factor for computing the pixel size range to be used for an image. This defines the maximum factor that a pixel will be subsampled by. By default, this is 5.2.

Build parameters
Derived images

Field

Description

Output folder

The default output folder to which the derived rasters are generated. If undefined, it will be in the same location and have the same name as the .ISDef folder; however, it will have the extension .DerivedImages.

Optimum number of cols

Optimum number of image columns in a derived image. The larger the value, the bigger the file and the more likely that the image would have to be regenerated if a higher-resolution image changes. The smaller the value, the more files created. The value 5120 is a reasonable default.

Optimum number of rows

Optimum number of image rows in an overview image. The larger the value, the bigger the file and the more likely that the image would have to be regenerated if a higher-resolution image changes. The smaller the value, the more files created. The value 5120 is a reasonable default.

Overlap pixels

Number of overlapping pixels that should be between derived rasters. Having some overlap is advantageous because it limits the number of pixels at the very edge of any image. This overlap should be small; otherwise, the file size increases. The value 5 is a reasonable default.

Format

Format to be used for the creation of derived rasters. This can be TIFF or JPEG 2000. TIFF is generally the most efficient.

Compression method

Method of compression used for the creation of derived rasters. This can be JPEG, JPEG 2000, and LZ77. JPEG is generally the most efficient.

Compression quality

Compression quality to be used for the creation of derived rasters. A value of 80 is commonly used, as it provides good compression with fewer visible artifacts.

Tile size

Tile size to be used (for TIFF) for the creation of derived rasters. For JPEG, a value of 0 means none are tiled. Using tiled images provides faster access to large rasters.

Sampling method

Sampling method to be used for the creation of derived rasters and derived tiles.

Overview factor

The factor to be used for the generation of overviews. The value can be 2, 3, 4, or 5. A factor of 2 results in an additional 33 percent imagery if service overviews are defined for rasters that have no internal overviews and the same compression is used. A factor of 3 results in an additional 13 percent.

Skip existing images

Used to control partial pyramiding if any raster datasets change. By default, this box is unchecked. When unchecked, partial pyramiding is turned on and derived images are regenerated if higher-resolution raster datasets are modified. When you check this option, only derived images that have not yet been created are generated while optimizing the image service definition.

Learn about deriving images for image service definition optimization

Overview sampling method

Sampling method to be used while creating overviews. Nearest neighbor is the fastest to create; it maintains the best radiometry but can result in high-contrast overviews and is generally not recommended. Bilinear interpolation is a standard method, but it results in the averaging of an image when using a factor of 2 that can result in low-contrast overviews. Cubic convolution can also be termed as bicubic interpolation. The output interpolated pixel value is calculated using the 16 closest pixels of the input.

Compute pixel size ranges

By default, this check box is checked, which implies that the pixel sizes of all raster datasets will be computed after the overviews are defined. When you uncheck this option, the pixel sizes will not be computed.

Clip overviews to boundary

By default, this check box is checked, which implies that the service overviews will be clipped with the boundary. When you uncheck this option, it can lead to artifacts around the valid data pixels.

Derived images parameters
Seamline parameters

Field

Description

Feather width

Defines the default value of feather width when creating seamlines.

Feather width unit

Defines the unit (in pixels or meters) in which the feather width is specified. The feather width defines the size of the blending between rasters. If in pixels, the width is a multiple of the output pixels. If in meters, the width is set to a fixed size.

Seamline type

Defines the type of seamline, either around or inside. In the around mode, feathering occurs on both sides of the seamline and is used when mosaicking aerial or satellite imagery. With the inside mode, feathering is only applied to the inside of the raster and is used when the extents of rasters are used (in terrain models, for example).

Minimum Overlap Tolerance

By default, the value is 20%. All the intersecting rasters that cover less than this percentage will not be included in the processing.

Maximum Overlap Tolerance

By default, the value is 90%. All the intersecting rasters that cover more than this percentage will not be included in the processing.

Seamline Granularity

Defines the pixel resolution of the image data in meters that is used to derive the seamlines.

Seamline parameters

Field Properties

This displays a table that defines all fields in the raster table that exist or can exist along with the properties of the selected field. This is used to control different properties of fields and how data in these fields is populated. Each raster can have a large number of different metadata attributes associated with it and stored in the associated raster process definition file. This metadata is generally not copied into the attributes of each field as it is often not required and could make the table very large.

Image Server includes a feature by which some or all of these attributes can be copied into the raster table during the build process. Some metadata fields from the raster process definition are required in the table for either data management or for the Order By Attribute mosaic method. When a raster is added, an .RPDef file is created; if there are attributes for the raster, the associated field names are added to the fields in the raster table.

The following list contains the default fields created with every image service definition. For more information on these fields, see Working with the service table.

Field

Description

RasterID

Identification number of the raster. This is a unique ID generated for each raster.

RasterName

Name given to the raster. It need not be unique.

RasterType

Type of the raster source, either a standard raster dataset type, raster process definition, service overview, or derived tile.

RasterSrc

Source of the raster for the service; points to the raster dataset or raster process definition.

MinPS

Minimum pixel size. If a request is made for a pixel size lower than this, the raster is not considered. The value is computed during the build process.

MaxPS

Maximum pixel size. If a request is made for a pixel size higher than this, the raster is not considered. The value is computed during the build process.

LoPS

Lower pixel size; the smallest pixel size in the raster.

HiPS

Higher pixel size; the largest pixel size in the raster. If the raster has only one grid of pixels, this is the same as the LoPS value.

DispOrder

Order of display that overrides the order defined by the mosaic method if it is not 0. Values greater than 0 are displayed with lower priority. Values less than 0 are displayed with greater priority.

StatusID

Status ID; status updated by the build process that indicates if there is a warning or error related to the raster. Positive values indicate a warning. Negative values indicate an error. A value of 0 indicates that the operation was successful.

StatusMsg

Status message; descriptive message associated with the statusID.

Fid

Feature ID of the footprint; part of a shapefile definition.

Shape

Shape of the footprint; part of a shapefile definition.

Service table default fields

You can use the Add Field and Delete Field buttons to add and remove the fields. The Extract From Layer button Extract fields from layer enables you to extract the additional fields in the shapefile that are not in the list of fields on the Image Service Properties—Field Properties dialog box. These extracted fields are added to the service table of the image service.

For each field, the following properties are defined:

Property

Description

Name

Name of the field.

Type

Type of the field, for example, primary, derived, metadata, and private.

Auto create

If checked, the fields are created during the build process when using the Extract metadata option.

Data type

Data type of the field, for example, string, int, float, and date.

Width

Maximum number of characters allowed.

Precision

Denotes the precision of the field or number of decimal places.

Display width

The displayed width of the field in a grid in twips.

Visible

If unchecked, the particular field is not displayed in the grid.

Order

Order in which the field is arranged in the grid.

Frozen

If checked, the field is frozen and field position cannot be changed.

Description

Description of the field.

XPath

Sets the path for getting the field values from an XML file. By setting this path, you can extract information from .RPDefs to the table. For example, to add the raster source path to the service table, type the following in the XPath text box: //ImageServer/RasterProcessDefinition/Rasters/RasterSource. Extracting attributes from the .RPDef XML is used to enable the values to be returned to the users for display in the attribute table of the raster dataset. It also enables these values to be used with the By Attribute mosaic method. Multiple XPaths delimited by a semicolon can be defined. This is necessary when an attribute value is defined in different metadata XML nodes in different .RPDefs. This may occur when the data is being used from different raster types in the same service. The values are extracted from the .RPDef XMLs when using the Extract metadata option in Build. See Editing the XML files using XPaths to search and replace values in an XML file using XPath.

Properties of additional fields

相关主题


7/10/2012