ImageHistogramParameters | API Reference | ArcGIS Maps SDK for JavaScript

Input parameters for the computeHistograms or computeStatisticsHistograms method on ImageryLayer, or the computeStatisticsHistograms method on ImageryTileLayer.

See also

Constructors

ImageHistogramParameters Constructor new ImageHistogramParameters(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 Watch for changes topic.

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Type	Summary	Class
String	The name of the class.	Accessor
Extent\|Polygon\|null\|undefined	Input geometry that defines the area of interest for which the histograms and statistics will be computed.	ImageHistogramParameters
MosaicRule\|null\|undefined	Specifies the mosaic rule on how individual images should be mosaicked when the histogram is computed.	ImageHistogramParameters
Point	Specifies the pixel size (or the resolution).	ImageHistogramParameters
RasterFunction\|null\|undefined	Specifies the raster function from which to compute the statistics and histogram.	ImageHistogramParameters
TimeExtent\|null\|undefined	The time extent for which to compute the statistics and histogram.	ImageHistogramParameters

Property Details

declaredClass Inherited Property declaredClass Stringreadonly Inherited from Accessor

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

geometry Property geometry Extent |Polygon |null |undefinedautocast

Input geometry that defines the area of interest for which the histograms and statistics will be computed. The geometry can be an extent or a polygon.

mosaicRule Property mosaicRule MosaicRule |null |undefinedautocast

Specifies the mosaic rule on how individual images should be mosaicked when the histogram is computed. When a mosaic rule is not specified, the current settings on the ImageryLayer will be used.

pixelSize Property pixelSize Pointautocast

Specifies the pixel size (or the resolution). If pixel size is not specified, pixelSize will default to the base resolution of the image service. The raster at the specified pixel size in the mosaic dataset will be used for the histogram calculation.

Example

// set the pixel size parameter to match the current
// resolution of the view and spatial reference
let pixelSize = {
  x:view.resolution,
  y:view.resolution,
  spatialReference: view.spatialReference
}
// set the histogram parameters to request
// data for the current view extent and resolution
let params = new ImageHistogramParameters({
  geometry:  view.extent,
  pixelSize: pixelSize
});

// request for histograms for the specified parameters
layer.computeHistograms(params).then((results) =>{
  // results are returned and process it as needed.
  console.log("histograms", result);
})
.catch(function(err){
  console.log("err", err)
});

rasterFunction Property rasterFunction RasterFunction |null |undefinedautocast Since: ArcGIS Maps SDK for JavaScript 4.27 ImageHistogramParameters since 4.20, rasterFunction added at 4.27.

Specifies the raster function from which to compute the statistics and histogram. The rasterFunction defines how the image should be processed. When a renderingRule is not specified, the current settings on the ImageryLayer will be used.

timeExtent Property timeExtent TimeExtent |null |undefinedautocast

The time extent for which to compute the statistics and histogram. The time parameter is supported at ArcGIS Server 10.8 and later.

Method Overview

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Return Type	Summary	Class
	Adds one or more handles which are to be tied to the lifecycle of the object.	Accessor
*\|null\|undefined	Creates a new instance of this class and initializes it with values from a JSON object generated from an ArcGIS product.	ImageHistogramParameters
Boolean	Returns true if a named group of handles exist.	Accessor
	Removes a group of handles owned by the object.	Accessor
Object	Converts an instance of this class to its ArcGIS portal JSON representation.	ImageHistogramParameters

Method Details

addHandles Inherited Method addHandles(handleOrHandles, groupKey) Inherited from Accessor Since: ArcGIS Maps SDK for JavaScript 4.25 Accessor since 4.0, addHandles added at 4.25.

Adds one or more handles which are to be tied to the lifecycle of the object. The handles will be removed when the object is destroyed.

// Manually manage handles
const handle = reactiveUtils.when(
  () => !view.updating,
  () => {
    wkidSelect.disabled = false;
  },
  { once: true }
);

this.addHandles(handle);

// Destroy the object
this.destroy();

Parameters

handleOrHandles WatchHandle|WatchHandle []

Handles marked for removal once the object is destroyed.

groupKey *

optional

Key identifying the group to which the handles should be added. All the handles in the group can later be removed with Accessor.removeHandles(). If no key is provided the handles are added to a default group.

fromJSON Method fromJSON(json){* |null |undefined}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
* \| null \| undefined	Returns a new instance of this class.

hasHandles Inherited Method hasHandles(groupKey){Boolean} Inherited from Accessor Since: ArcGIS Maps SDK for JavaScript 4.25 Accessor since 4.0, hasHandles added at 4.25.

Returns true if a named group of handles exist.

Parameter

groupKey *

optional

A group key.

Returns

Type	Description
Boolean	Returns `true` if a named group of handles exist.

Example

// Remove a named group of handles if they exist.
if (obj.hasHandles("watch-view-updates")) {
  obj.removeHandles("watch-view-updates");
}

removeHandles Inherited Method removeHandles(groupKey) Inherited from Accessor Since: ArcGIS Maps SDK for JavaScript 4.25 Accessor since 4.0, removeHandles added at 4.25.

Removes a group of handles owned by the object.

Parameter

groupKey *

optional

A group key or an array or collection of group keys to remove.

Example

obj.removeHandles(); // removes handles from default group

obj.removeHandles("handle-group");
obj.removeHandles("other-handle-group");

toJSON Method 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.