The ImageData()
constructor returns a newly instantiated ImageData
object built from the typed array given and having the specified width and height.
This constructor is the preferred way of creating such an object in a Worker
.
new ImageData(array, width [, height]); new ImageData(width, height);
array
Optional
Uint8ClampedArray
containing the underlying pixel representation of the image. If no such array is given, an image with a black rectangle of the specified width
and height
will be created.width
height
A new ImageData
object.
IndexSizeError
array
is specified, but its length is not a multiple of (4 * width)
or (4 * width * height)
.This example creates an ImageData
object that is 200 pixels wide and 100 pixels tall, containing a total of 20,000 pixels.
let imageData = new ImageData(200, 100); // ImageData { width: 200, height: 100, data: Uint8ClampedArray[80000] }
This example instantiates an ImageData
object with pixel colors defined by an array.
<canvas id="canvas"></canvas>
The array (arr
) has a length of 40000
: it consists of 10,000 pixels, each of which is defined by 4 values. The ImageData
constructor specifies a width
of 200
for the new object, so its height
defaults to 10,000 divided by 200, which is 50
.
const canvas = document.getElementById('canvas'); const ctx = canvas.getContext('2d'); const arr = new Uint8ClampedArray(40000); // Iterate through every pixel for (let i = 0; i < arr.length; i += 4) { arr[i + 0] = 0; // R value arr[i + 1] = 190; // G value arr[i + 2] = 0; // B value arr[i + 3] = 255; // A value } // Initialize a new ImageData object let imageData = new ImageData(arr, 200); // Draw image data to the canvas ctx.putImageData(imageData, 20, 20);
Specification | Status | Comment |
---|---|---|
HTML Living Standard The definition of 'ImageData()' in that specification. | Living Standard | Initial definition. |
Desktop | ||||||
---|---|---|---|---|---|---|
Chrome | Edge | Firefox | Internet Explorer | Opera | Safari | |
Basic support | 42 | Yes | 29 | No | 29 | ? |
Mobile | |||||||
---|---|---|---|---|---|---|---|
Android webview | Chrome for Android | Edge Mobile | Firefox for Android | Opera for Android | iOS Safari | Samsung Internet | |
Basic support | No | 42 | ? | 29 | ? | ? | 4.0 |
CanvasRenderingContext2D.createImageData()
, the creator method that can be used outside workers.
© 2005–2018 Mozilla Developer Network and individual contributors.
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/API/ImageData/ImageData