createImageBitmap() global function
The createImageBitmap()
method creates a bitmap from a
given source, optionally cropped to contain only a portion of that source. The method
exists on the global scope in both windows and workers. 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 whether the image should be presented as is or flipped vertically. Either
none
(default) orflipY
. premultiplyAlpha
-
Specifies whether the bitmap's color channels should be premultiplied by the alpha channel. One of
none
,premultiply
, ordefault
(default). colorSpaceConversion
-
Specifies whether the image should be decoded using color space conversion. Either
none
ordefault
(default). The valuedefault
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
, orhigh
.
Return value
A Promise
which resolves to an ImageBitmap
object
containing bitmap data from the given rectangle.
Examples
Creating sprites from a sprite sheet
This example loads a sprite sheet, extracts individual sprites, and then renders each sprite to the canvas. A sprite sheet is an image containing multiple smaller images, each of which you want to be able to render separately.
js
const canvas = document.getElementById("myCanvas"),
ctx = canvas.getContext("2d"),
image = new Image();
// Wait for the sprite sheet to load
image.onload = () => {
Promise.all([
// Cut out two sprites from the sprite sheet
createImageBitmap(image, 0, 0, 32, 32),
createImageBitmap(image, 32, 0, 32, 32),
]).then((sprites) => {
// Draw each sprite onto the canvas
ctx.drawImage(sprites[0], 0, 0);
ctx.drawImage(sprites[1], 32, 32);
});
};
// Load the sprite sheet from an image file
image.src = "sprites.png";
Specifications
Specification |
---|
HTML Standard # dom-createimagebitmap-dev |
Browser compatibility
BCD tables only load in the browser