WorkerGlobalScope: createImageBitmap() method

Note: This feature is only available in Web Workers.

The createImageBitmap() method of the WorkerGlobalScope interface creates a bitmap from a given source, optionally cropped to contain only a portion of that source. It accepts a variety of different image sources, and returns a Promise which resolves to an ImageBitmap.

Syntax

js
createImageBitmap(image)
createImageBitmap(image, options)
createImageBitmap(image, sx, sy, sw, sh)
createImageBitmap(image, sx, sy, sw, sh, options)

Parameters

image

An image source, which can be any one of the following:

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 image's extraction. The available options are:

imageOrientation

Specifies how the bitmap image should be oriented.

from-image

Image oriented according to EXIF orientation metadata, if present (default).

flipY

Image oriented according to EXIF orientation metadata, if present, and then flipped vertically.

none

Image oriented according to image encoding, ignoring any metadata about the orientation (such as EXIF metadata, that might be added to an image to indicate that the camera was turned sideways to capture the image in portrait mode).

premultiplyAlpha

Specifies whether the bitmap's color channels should be premultiplied by the alpha channel. One of none, premultiply, or default (default).

colorSpaceConversion

Specifies whether the image should be 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 output width.

resizeHeight

A long integer that indicates the output height.

resizeQuality

Specifies the algorithm to be used for resizing the input to match the output dimensions. 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.

Examples

See Window.createImageBitmap() for examples.

Specifications

Specification
HTML Standard
# dom-createimagebitmap-dev

Browser compatibility

BCD tables only load in the browser

See also