RasterFunction

AMD: require(["esri/layers/support/RasterFunction"], (RasterFunction) => { /* code goes here */ });
ESM: import RasterFunction from "@arcgis/core/layers/support/RasterFunction";
Class: esri/layers/support/RasterFunction
Inheritance: RasterFunction Accessor
Since: ArcGIS API for JavaScript 4.0

Raster functions specify processing to be done to the image service. They allow the mosaic image service to deliver a dynamically mosaicked image and they can be used to enhance the mosaicked image product by applying processing operations such as image enhancements, and image algebra. See raster functions for a list of functions and their arguments. The following image shows a landcover ImageryLayer rendered with two chained client-side raster functions used to reclass pixel values (Remap) and assign each pixel a new color (Colormap).

layers-imagery-rf

Chaining raster functions is accomplished by setting the Raster argument in the functionArguments property to another defined raster function. See example below on chaining a Remap raster function with a Colormap.

let remapRF = new RasterFunction();
remapRF.functionName = "Remap";
remapRF.functionArguments = {
  InputRanges: [-3,10,11,37], // remap pixels with values -3 to 10 to now have value of 1
  OutputValues: [1,2],        // remap pixel values from 11 to 37 to have a value of 2
  Raster: "$$"  // Apply remap to the image service
};
remapRF.outputPixelType = "u8";

let colorRF = new RasterFunction();
colorRF.functionName = "Colormap";
colorRF.functionArguments = {
  Colormap: [
    [1, 255, 0, 0],  // Symbolize pixels with value of 1 using red color
    [2, 0, 255, 0]   // Symbolize pixels with value of 2 using green color
  ],
  Raster : remapRF  // Apply Colormap to output raster from the remap rasterFunction
};

imageLayer.renderingRule = colorRF; // Set rendering rule to final raster function
See also:

Constructors

new RasterFunction(properties)
Parameter:
properties Object
optional

See the properties for a list of all the properties that may be passed into the constructor.

Property Overview

Any properties can be set, retrieved or listened to. See the Working with Properties topic.
Show inherited properties Hide inherited properties
Name Type Summary Class
Stringmore details

The name of the class.

more detailsAccessor
Objectmore details

The arguments for the raster function.

more detailsRasterFunction
Stringmore details

The raster function name.

more detailsRasterFunction
Stringmore details

Defines the pixel type of the output image.

more detailsRasterFunction
Stringmore details

The variable name for the raster function.

more detailsRasterFunction

Property Details

declaredClass Stringreadonly inherited
Since: ArcGIS API for JavaScript 4.7

The name of the class. The declared class name is formatted as esri.folder.className.

functionArguments Object

The arguments for the raster function. The structure depends on the function specified. See raster functions for a list of functions and their arguments. Also parses the arguments of RFT format.

Example:
rasterFunction.functionArguments = {
  "Azimuth":215.0,
  "Altitude":75.0,
  "ZFactor":0.3
};
functionName String

The raster function name. See raster functions for a list of functions and their arguments. The name in the raster function in RFT JSON format is also parsed to functionName.

Example:
rasterFunction.functionName = "Stretched";
rasterFunction.name = "GrayScale";
outputPixelType String

Defines the pixel type of the output image.

Possible Values:"c128"|"c64"|"f32"|"f64"|"s16"|"s32"|"s8"|"u1"|"u16"|"u2"|"u32"|"u4"|"u8"|"unknown"

Default Value:unknown
Example:
rasterFunction.outputPixelType = "u8";
variableName String

The variable name for the raster function.

Example:
rasterFunction.variableName = "DEM";

Method Overview

Name Return Type Summary Class
*more details

Creates a new instance of this class and initializes it with values from a JSON object generated from an ArcGIS product.

more detailsRasterFunction
Objectmore details

Converts an instance of this class to its ArcGIS portal JSON representation.

more detailsRasterFunction

Method Details

fromJSON(json){*}static

Creates a new instance of this class and initializes it with values from a JSON object generated from an ArcGIS product. The object passed into the input json parameter often comes from a response to a query operation in the REST API or a toJSON() method from another ArcGIS product. See the Using fromJSON() topic in the Guide for details and examples of when and how to use this function.

Parameter:
json Object

A JSON representation of the instance in the ArcGIS format. See the ArcGIS REST API documentation for examples of the structure of various input JSON objects.

Returns:
Type Description
* Returns a new instance of this class.
toJSON(){Object}

Converts an instance of this class to its ArcGIS portal JSON representation. See the Using fromJSON() guide topic for more information.

Returns:
Type Description
Object The ArcGIS portal JSON representation of an instance of this class.

Your browser is no longer supported. Please upgrade your browser for the best experience. See our browser deprecation post for more details.