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.
Experimental: This is an experimental technology
Check the Browser compatibility table carefully before using this in production.
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 aReadableStream
of bytes representing an encoded image type as described bytype
. premultiplyAlpha
Optional-
Specifies whether the decoded image's color channels should be premultiplied by the alpha channel. If not provided set as
"default"
:"none"
"premultiply"
"default"
colorSpaceConversion
Optional-
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"
desiredWidth
Optional-
An integer indicating the desired width for the decoded output. Has no effect unless the image codec supports variable resolution decoding.
desiredHeight
Optional-
An integer indicating the desired height for the decoded output. Has no effect unless the image codec supports variable resolution decoding.
preferAnimation
Optional-
A
Boolean
indicating whether the initial track selection should prefer an animated track. transfer
-
An array of
ArrayBuffer
s thatImageDecoder
will detach and take ownership of. If the array contains theArrayBuffer
backingdata
,ImageDecoder
will 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 |
Browser compatibility
BCD tables only load in the browser