ImageDecoder: ImageDecoder() constructor
Limited availability
This feature is not Baseline because it does not work in some of the most widely-used browsers.
Secure context: This feature is available only in secure contexts (HTTPS), in some or all supporting browsers.
Note: This feature is available in Dedicated Web Workers.
The ImageDecoder() constructor creates a new ImageDecoder object which unpacks and decodes image data.
Syntax
new ImageDecoder(init)
Parameters
init-
An object containing the following members:
type-
A string containing the MIME type of the image file to be decoded.
data-
An
ArrayBuffer, aTypedArray, aDataView, or aReadableStreamof bytes representing an encoded image type as described bytype. premultiplyAlphaOptional-
Specifies whether the decoded image's color channels should be premultiplied by the alpha channel. If not provided set as
"default":"none""premultiply""default"
colorSpaceConversionOptional-
Specifies whether the image should be decoded using color space conversion. If not provided set as
"default". The value"default"indicates that implementation-specific behavior is used:"none""default"
desiredWidthOptional-
An integer indicating the desired width for the decoded output. Has no effect unless the image codec supports variable resolution decoding.
desiredHeightOptional-
An integer indicating the desired height for the decoded output. Has no effect unless the image codec supports variable resolution decoding.
preferAnimationOptional-
A
Booleanindicating whether the initial track selection should prefer an animated track. transfer-
An array of
ArrayBuffers thatImageDecoderwill detach and take ownership of. If the array contains theArrayBufferbackingdata,ImageDecoderwill use that buffer directly instead of copying from it.
Examples
The following example creates a new ImageDecoder with the required options.
let init = {
type: "image/png",
data: imageByteStream,
};
let imageDecoder = new ImageDecoder(init);
Specifications
| Specification |
|---|
| WebCodecs> # dom-imagedecoder-imagedecoder> |