lossless-jpeg-decoder v1.0.0

lossless-jpeg-decoder

Decoder for lossless JPEG compression.

Usage

The module returns a decoder class with the following interface:

• decode(TypedArray inputBuffer, [TypedArray outputBuffer], [Number sliceSize]): Decodes the JPEG stored in inputBuffer. If outputBuffer is given it will be used to store the decoded image. If sliceSize is given it will be used as length for each line. This us useful for tiled decoding or WebGL textures with a size of 2^x.
• close(): Will destroy WebWorkers, if they are used for decoding (currently not implemented).

Example

// load the LosslessJpegDecoder class
const LosslessJpegDecoder = require('lossless-jped-decoder')

// create an instance
let decoder = new LosslessJpegDecoder()

// input must be the JPEG binary as TypedArray
let input = new Uint8Array()

// decode the JPEG
decoder.decode(input).then((image) => {
  // log all image properties 
  console.log('image width: ' + image.width)
  console.log('image height: ' + image.height)
  console.log('number of components: ' + image.components)
  console.log('width of each line in the buffer: ' + image.bufferWidth)
  console.log('number of elements in the buffer: ' + buffer.length)

  // close the decoder (if WebWorkers were used, will destroy them)
  decoder.close()
})