WindowOrWorkerGlobalScope.createImageBitmap()

The createImageBitmap method of the WindowOrWorkerGlobalScope mixin accepts a variety of different image sources, and returns a Promise which resolves to an ImageBitmap. Optionally the source is cropped to the rectangle of pixels originating at (sx, sy) with width sw, and height sh.

Syntax

createImageBitmap(image[, options]).then(function(response) { ... });
createImageBitmap(image, sx, sy, sw, sh[, options]).then(function(response) { ... });

Parameters

image

An image source, which can be an <img>, SVG <image>, <video>, <canvas>, HTMLImageElement, SVGImageElement, HTMLVideoElement, HTMLCanvasElement, Blob, ImageData, ImageBitmap, or OffscreenCanvas object.

sx

The x coordinate of the reference point of the rectangle from which the ImageBitmap will be extracted.

sy

The y coordinate of the reference point of the rectangle from which the ImageBitmap will be extracted.

sw

The width of the rectangle from which the ImageBitmap will be extracted. This value can be negative.

sh

The height of the rectangle from which the ImageBitmap will be extracted. This value can be negative.

options Optional

An object that sets options for . The available options are:

• imageOrientation: Indicates whether the image is presented as is or flipped vertically. Either none (default) or flipY.
• premultiplyAlpha: Indicates that the bitmaps color channels are premultiplied by the alpha channel. One of none, premultiply, or default (default).
• colorSpaceConversion: Indicates whether the image is decoded using color space conversion. Either none or default (default). The value default indicates that implementation-specific behavior is used.
• resizeWidth: A long integer that indicates the new width.
• resizeHeight: A long integer that indicates the new height.
• resizeQuality: Specifies an image scaling algorithm. One of pixelated, low (default), medium, or high.

Return value

A Promise which resolves to an ImageBitmap object containing bitmap data from the given rectangle.

Example

var canvas = document.getElementById('myCanvas'),
ctx = canvas.getContext('2d'),
image = new Image();
image.onload = function() {
  Promise.all([
    createImageBitmap(this, 0, 0, 32, 32),
    createImageBitmap(this, 32, 0, 32, 32)
  ]).then(function(sprites) {
    ctx.drawImage(sprites[0], 0, 0);
    ctx.drawImage(sprites[1], 32, 32);
  });
}
image.src = 'sprites.png';

Specifications

Browser compatibility

[1] createImageBitmap() now defined on WindowOrWorkerGlobalScope mixin.

See also

• CanvasRenderingContext2D.drawImage()
• ImageData