OpenLayers v4.0.1 API - Class: Raster

# Class: Raster

This documentation is for OpenLayers v4.0.1. The latest is v.

## ol.source.Raster

A source that transforms data from any number of input sources using an array of `ol.RasterOperation` functions to transform input pixel values into output pixel values.

#### new ol.source.Raster(options)

src/ol/source/raster.js, line 36

  Name | Type | Description
  --- | --- | ---

  `options`

  Options.

  Name | Type | Description
  --- | --- | ---
  `sources` | Array.<ol.source.Source> | Input sources. Required.
  `operation` | ol.RasterOperation | undefined | Raster operation. The operation will be called with data from input sources and the output will be assigned to the raster source.
  `lib` | Object | undefined | Functions that will be made available to operations run in a worker.
  `threads` | number | undefined | By default, operations will be run in a single worker thread. To avoid using workers altogether, set `threads: 0`. For pixel operations, operations can be run in multiple worker threads. Note that there is additional overhead in transferring data to multiple workers, and that depending on the user's system, it may not be possible to parallelize the work.
  `operationType` | ol.source.RasterOperationType | undefined | Operation type. Supported values are `'pixel'` and `'image'`. By default, `'pixel'` operations are assumed, and operations will be called with an array of pixels from input sources. If set to `'image'`, operations will be called with an array of ImageData objects from input sources.

  ##### Fires:

  - `afteroperations` (ol.source.Raster.Event) - Triggered after operations are run.
  - `beforeoperations` (ol.source.Raster.Event) - Triggered before operations are run.
  - `change` (ol.events.Event) - Generic change event. Triggered when the revision counter is increased.
  - `propertychange` (ol.Object.Event) - Triggered when a property is changed.

### Extends

- ol.source.Image

### Classes

Event

### Methods

#### changed() inherited

src/ol/observable.js, line 58

  Increases the revision counter and dispatches a 'change' event.

#### dispatchEvent(event) inherited

src/ol/observable.js, line 75

  Dispatches an event and calls all listeners listening for events of this type. The event parameter can either be a string or an Object with a `type` property.

  Name | Type | Description
  --- | --- | ---
  `event` | Object | ol.events.Event | string | Event object.

#### get(key){*} inherited

src/ol/object.js, line 101

  Gets a value.

  Name | Type | Description
  --- | --- | ---
  `key` | string | Key name.

  ##### Returns:

  Value.

#### getAttributions(){Array.<ol.Attribution>} inherited

src/ol/source/source.js, line 113

  Get the attributions of the source.

  ##### Returns:

  Attributions.

#### getKeys(){Array.<string>} inherited

src/ol/object.js, line 115

  Get a list of object property names.

  ##### Returns:

  List of property names.

#### getLogo(){string|olx.LogoOptions|undefined} inherited

src/ol/source/source.js, line 123

  Get the logo of the source.

  ##### Returns:

  Logo.

#### getProjection(){ol.proj.Projection} inherited

src/ol/source/source.js, line 133

  Get the projection of the source.

  ##### Returns:

  Projection.

#### getProperties(){Object.<string, *>} inherited

src/ol/object.js, line 125

  Get an object of all property names and values.

  ##### Returns:

  Object.

#### getRevision(){number} inherited

src/ol/observable.js, line 84

  Get the version number for this object. Each time the object is modified, its version number will be incremented.

  ##### Returns:

  Revision.

#### getState(){ol.source.State} inherited

src/ol/source/source.js, line 150

  Get the state of the source, see `ol.source.State` for possible states.

  ##### Returns:

  State.

#### on(type, listener, opt_this){ol.EventsKey|Array.<ol.EventsKey>} inherited

src/ol/observable.js, line 99

  Listen for a certain type of event.

  Name | Type | Description
  --- | --- | ---
  `type` | string | Array.<string> | The event type or array of event types.
  `listener` | function | The listener function.
  `this` | Object | The object to use as `this` in `listener`.

  ##### Returns:

  Unique key for the listener. If called with an array of event types as the first argument, the return will be an array of keys.

#### once(type, listener, opt_this){ol.EventsKey|Array.<ol.EventsKey>} inherited

src/ol/observable.js, line 124

  Listen once for a certain type of event.

  Name | Type | Description
  --- | --- | ---
  `type` | string | Array.<string> | The event type or array of event types.
  `listener` | function | The listener function.
  `this` | Object | The object to use as `this` in `listener`.

  ##### Returns:

  Unique key for the listener. If called with an array of event types as the first argument, the return will be an array of keys.

#### refresh() inherited

src/ol/source/source.js, line 167

  Refreshes the source and finally dispatches a 'change' event.

#### set(key, value, opt_silent) inherited

src/ol/object.js, line 150

  Sets a value.

  Name | Type | Description
  --- | --- | ---
  `key` | string | Key name.
  `value` | * | Value.
  `silent` | boolean | Update without triggering an event.

#### setAttributions(attributions) inherited

src/ol/source/source.js, line 179

  Set the attributions of the source.

  Name | Type | Description
  --- | --- | ---
  `attributions` | ol.AttributionLike | undefined | Attributions. Can be passed as `string`, `Array<string>`, ``ol.Attribution``, `Array<`ol.Attribution`>` or `undefined`.

#### setOperation(operation, opt_lib)

src/ol/source/raster.js, line 150

  Set the operation.

  Name | Type | Description
  --- | --- | ---
  `operation` | ol.RasterOperation | New operation.
  `lib` | Object | Functions that will be available to operations run in a worker.

#### setProperties(values, opt_silent) inherited

src/ol/object.js, line 170

  Sets a collection of key-value pairs. Note that this changes any existing properties and adds new ones (it does not remove any existing properties).

  Name | Type | Description
  --- | --- | ---
  `values` | Object.<string, *> | Values.
  `silent` | boolean | Update without triggering an event.

#### un(type, listener, opt_this) inherited

src/ol/observable.js, line 147

  Unlisten for a certain type of event.

  Name | Type | Description
  --- | --- | ---
  `type` | string | Array.<string> | The event type or array of event types.
  `listener` | function | The listener function.
  `this` | Object | The object which was used as `this` by the `listener`.

#### unset(key, opt_silent) inherited

src/ol/object.js, line 184

  Unsets a property.

  Name | Type | Description
  --- | --- | ---
  `key` | string | Key name.
  `silent` | boolean | Unset without triggering an event.