An object representing the pixel arrays in the view. It stores and decodes source data fetched from an image service associated with an ImageryLayer. This provides the user access to each pixel on the client via the pixels property. The PixelBlock object is designed to handle generic pixel arrays from any raster data source.
Constructors
-
new PixelBlock(properties)
-
Parameterproperties Objectoptional
See the properties for a list of all the properties that may be passed into the constructor.
Property Overview
Name | Type | Summary | Class |
---|---|---|---|
String | The name of the class. more details | Accessor | |
Number | The height (or number of rows) of the PixelBlock in pixels. more details | PixelBlock | |
Number[]|Uint8Array | An array of nodata mask. more details | PixelBlock | |
Boolean | Indicates whether mask should be used as alpha values. more details | PixelBlock | |
Number[][]|Int8Array[]|Uint8Array[]|Uint8ClampedArray[]|Int16Array[]|Uint16Array[]|Int32Array[]|Uint32Array[]|Float32Array[]|Float64Array[] | A two dimensional array representing the pixels from the Image Service displayed on the client. more details | PixelBlock | |
String | The pixel type. more details | PixelBlock | |
Object[] | An array of objects containing numeric statistical properties. more details | PixelBlock | |
Number | Number of valid pixels more details | PixelBlock | |
Number | The width (or number of columns) of the PixelBlock in pixels. more details | PixelBlock |
Property Details
-
Since: ArcGIS Maps SDK for JavaScript 4.7
-
The name of the class. The declared class name is formatted as
esri.folder.className
.
-
height Number
-
The height (or number of rows) of the PixelBlock in pixels.
-
-
An array of nodata mask. All pixels are valid when mask is null.
-
maskIsAlpha Boolean
-
Indicates whether mask should be used as alpha values. If no (default), a pixel is valid when corresponding mask value is truthy
-
A two dimensional array representing the pixels from the Image Service displayed on the client. The length of the first dimension is the same as the number of bands in the layer. The length of the second dimension is height * width. The length of each band is the same. The pixels in each band are arranged row by row in this format:
[p_00, p_10, p_20, ... p_10, p_11, ...]
wherep_xy
is the pixel value at the columnx
and rowy
.Examplelet pixels = imgLyr.pixelData.pixelBlock.pixels; // Prints the number of bands in the layer console.log(pixels.length); // An array containing all the pixels in the first band let band1 = pixels[0];
-
pixelType String
-
The pixel type.
Possible Values:"unknown"|"s8"|"s16"|"s32"|"u8"|"u16"|"u32"|"f32"|"f64"
-
An array of objects containing numeric statistical properties. Each object has the following specification if defined.
-
validPixelCount Number
-
Number of valid pixels
-
width Number
-
The width (or number of columns) of the PixelBlock in pixels.
Method Overview
Name | Return Type | Summary | Class |
---|---|---|---|
Adds another plane to the PixelBlock. more details | PixelBlock | ||
Adds one or more handles which are to be tied to the lifecycle of the object. more details | Accessor | ||
Uint8ClampedArray | Returns pixels and masks using a single array in bip format (e.g. more details | PixelBlock | |
Float32Array | Similar to getAsRGBA, but returns floating point data. more details | PixelBlock | |
Number | Returns the plane band count of the PixelBlock. more details | PixelBlock | |
Boolean | Returns true if a named group of handles exist. more details | Accessor | |
Removes a group of handles owned by the object. more details | Accessor |
Method Details
-
addData(planeData)
-
Adds another plane to the PixelBlock.
ParametersSpecificationplaneData ObjectThe data to add to the PixelBlock.
SpecificationA two dimensional array representing the pixels to add.
An array of objects containing numeric statistical properties. See statistics for details on the specifications of each object.
-
addHandles(handleOrHandles, groupKey)inheritedSince: ArcGIS Maps SDK for JavaScript 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();
ParametershandleOrHandles WatchHandle|WatchHandle[]Handles marked for removal once the object is destroyed.
groupKey *optionalKey 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.
-
getAsRGBA(){Uint8ClampedArray}
-
Returns pixels and masks using a single array in bip format (e.g. [p_00_r, p_00_g, p_00_b, p_00_a, p_10_r, p_10_g, p_10_b, p_10_a, .....]). Use this method to get an unsigned 8 bit pixel array. The result can be used to create a webgl texture.
ReturnsType Description Uint8ClampedArray An unsigned 8-bit pixel array.
-
getAsRGBAFloat(){Float32Array}
-
Similar to getAsRGBA, but returns floating point data. The result can be used to create a webgl texture (OES_texture_float).
ReturnsType Description Float32Array A floating point array.
-
getPlaneCount(){Number}
-
Returns the plane band count of the PixelBlock.
ReturnsType Description Number The plane band count.
-
Since: ArcGIS Maps SDK for JavaScript 4.25
-
Returns true if a named group of handles exist.
ParametergroupKey *optionalA group key.
ReturnsType 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(groupKey)inheritedSince: ArcGIS Maps SDK for JavaScript 4.25
-
Removes a group of handles owned by the object.
ParametergroupKey *optionalA group key or an array or collection of group keys to remove.
Exampleobj.removeHandles(); // removes handles from default group obj.removeHandles("handle-group"); obj.removeHandles("other-handle-group");