@cleerlycode/cornerstone-wado-image-loader/src/webWorker/decodeTask/decoders/decodeJPEGLossless.js

Cornerstone ImageLoader for DICOM WADO-URI

function decodeJPEGLossless (imageFrame, pixelData) {
  // check to make sure codec is loaded
  if (typeof jpeg === 'undefined' ||
    typeof jpeg.lossless === 'undefined' ||
    typeof jpeg.lossless.Decoder === 'undefined') {
    throw new Error('No JPEG Lossless decoder loaded');
  }

  const byteOutput = imageFrame.bitsAllocated <= 8 ? 1 : 2;
  // console.time('jpeglossless');
  const buffer = pixelData.buffer;
  const decoder = new jpeg.lossless.Decoder();
  const decompressedData = decoder.decode(buffer, pixelData.byteOffset, pixelData.length, byteOutput);
  // console.timeEnd('jpeglossless');

  if (imageFrame.pixelRepresentation === 0) {
    if (imageFrame.bitsAllocated === 16) {
      imageFrame.pixelData = new Uint16Array(decompressedData.buffer);

      return imageFrame;
    }
    // untested!
    imageFrame.pixelData = new Uint8Array(decompressedData.buffer);

    return imageFrame;

  }
  imageFrame.pixelData = new Int16Array(decompressedData.buffer);

  return imageFrame;

}

export default decodeJPEGLossless;