RasterColormapRenderer | References | ArcGIS Maps SDK for JavaScript

import RasterColormapRenderer from "@arcgis/core/renderers/RasterColormapRenderer.js";

Inheritance:: RasterColormapRenderer→Accessor

Since: ArcGIS Maps SDK for JavaScript 4.16

The RasterColormapRenderer defines the symbology to display raster data based on specific colors, aiding in visual analysis of the data. For example, a forestry commission may want to quickly visualize areas above and below the treeline occurring at a known elevation on a raster containing elevation values. They could overlay a transparent colormap set to color those areas below the treeline elevation green, and those above white.

The RasterColormapRenderer is only available if a color map is present in an ImageryLayer or ImageryTileLayer. Otherwise, you can use the UniqueValueRenderer to apply colors to your layer.

Constructors

Constructor

Parameters

Parameter	Type	Description	Required
properties	`RasterColormapRendererProperties`

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

Examples

// create a new RasterColormapRenderer from provided the colormap array
const renderer = RasterColormapRenderer.createFromColormap(colors);

// create a new RasterColormapRenderer
const renderer = new RasterColormapRenderer({
 colormapInfos: colormapInfos
});

Properties

Any properties can be set, retrieved or listened to. See the Watch for changes topic.

Property	Type	Class
`colormapInfos`	`ColormapInfo[]`
`declaredClass` readonly inherited	`string`	Accessor
`type` readonly	`"raster-colormap"`

colormapInfos

autocast Property

Type: ColormapInfo[]

A colormap info array containing mappings for pixel and RGB color values. Colormaps contain a set of values that are associated with colors and pixel values, and are used to display a single-band raster consistently with the same colors.

declaredClass

readonlyinherited Property

Type: string

Inherited from: Accessor

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

type

readonly Property

Type: "raster-colormap"

The type of Renderer.

Methods

Method	Signature	Class
`createFromColormap` static	`createFromColormap(colormap: number[][] \| null \| undefined): RasterColormapRenderer \| null`
`fromJSON` inherited static	`fromJSON(json: any): any`	JSONSupportMixin
`clone`	`clone(): RasterColormapRenderer`
`toJSON` inherited	`toJSON(): any`	JSONSupportMixin

createFromColormap

static Method

Signature: createFromColormap (colormap: number[][] | null | undefined): RasterColormapRenderer | null

Creates a new instance RasterColormapRenderer from an array of color maps where pixel values with its corresponding RGB color values specified.

Parameters

Parameter	Type	Description	Required
colormap	`number[][] \| null \| undefined`	RGB color representation of pixel values. Each item in the colormap array has an array of the pixel value and red, green, and blue values.

Returns: RasterColormapRenderer | null
Returns a new instance RasterColormapRenderer based on provided colormap.

Example

// create a color map where values 0-199 are pink and 200-250 are light blue.
let colors = [];
for (let i = 0; i <= 250; i++) {
  if (i < 200) {
    colors.push([i, 250, 0, 128]);
  } else {
    colors.push([i, 0, 128, 250]);
  }
}

// create a RasterColormapRenderer from the colors array
const renderer = RasterColormapRenderer.createFromColormap(colors);

fromJSON

inheritedstatic Method

Signature: fromJSON (json: any): any

Inherited from: JSONSupportMixin

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.

Parameters

Parameter	Type	Description	Required
json	`any`	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: any
Returns a new instance of this class.

clone

Method

Signature: clone (): RasterColormapRenderer

Creates a deep clone of the renderer.

Returns: RasterColormapRenderer
A deep clone of the object that invoked this method.

Example

// Creates a deep clone of the first layer's renderer
let renderer = view.map.layers.at(0).renderer.clone();

toJSON

inherited Method

Signature: toJSON (): any

Inherited from: JSONSupportMixin

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

Returns: any
The ArcGIS portal JSON representation of an instance of this class.