A common DICOM compression format is JPEG Lossless. This format is generally not supported in standard JPEG decoder libraries.

This decoder can read data from the following DICOM transfer syntaxes:

• 1.2.840.10008.1.2.4.57 JPEG Lossless, Nonhierarchical (Processes 14)
• 1.2.840.10008.1.2.4.70 JPEG Lossless, Nonhierarchical (Processes 14 [Selection 1])

API and more examples

var decoder = new jpeg.lossless.Decoder();
var output = decoder.decompress(buffer [, offset [, length]]);

// Parameters
// {ArrayBuffer} buffer
// {Number} offset offset into buffer (default = 0)
// {Number} length length of buffer (default = end of JPEG block)

// Returns
// {ArrayBuffer} output (size = cols * rows * bytesPerComponent * numComponents)

Get a packaged source file from the release folder:

• lossless.js
• lossless-min.js

Or install via NPM:

npm install jpeg-lossless-decoder-js

npm test

npm run build

This will output lossless.js and lossless-min.js alongside declaration files and source maps to /release.

This decoder was originally written by Helmut Dersch for Java. I added support for selection values 2 through 7, contributed bug fixes and ported to JavaScript.

Also thanks to @jens-ox for modernizing this package to TypeScript.