cornerstone-wado-image-loader
Version:
Cornerstone Image Loader for DICOM WADO-URI and WADO-RS
175 lines (127 loc) • 5.8 kB
HTML
<html lang="en">
<head>
<meta charset="utf-8">
<title>shared/decoders/decodeJPEGBaseline8Bit.js - Documentation</title>
<script src="scripts/prettify/prettify.js"></script>
<script src="scripts/prettify/lang-css.js"></script>
<!--[if lt IE 9]>
<script src="//html5shiv.googlecode.com/svn/trunk/html5.js"></script>
<![endif]-->
<link type="text/css" rel="stylesheet" href="styles/prettify.css">
<link type="text/css" rel="stylesheet" href="styles/jsdoc.css">
<script src="scripts/nav.js" defer></script>
<meta name="viewport" content="width=device-width, initial-scale=1.0">
</head>
<body>
<input type="checkbox" id="nav-trigger" class="nav-trigger" />
<label for="nav-trigger" class="navicon-button x">
<div class="navicon"></div>
</label>
<label for="nav-trigger" class="overlay"></label>
<nav >
<h2><a href="index.html">Home</a></h2><h3>Global</h3><ul><li><a href="global.html#addTask">addTask</a></li><li><a href="global.html#arrayBufferToString">arrayBufferToString</a></li><li><a href="global.html#cacheSizeInBytes">cacheSizeInBytes</a></li><li><a href="global.html#cancelTask">cancelTask</a></li><li><a href="global.html#decodeAsync">decodeAsync</a></li><li><a href="global.html#framesAreFragmented">framesAreFragmented</a></li><li><a href="global.html#getMinMax">getMinMax</a></li><li><a href="global.html#getNumberString">getNumberString</a></li><li><a href="global.html#getNumberValues">getNumberValues</a></li><li><a href="global.html#getStatistics">getStatistics</a></li><li><a href="global.html#getTransferSyntaxForContentType">getTransferSyntaxForContentType</a></li><li><a href="global.html#getUncompressedImageFrame">getUncompressedImageFrame</a></li><li><a href="global.html#getValue">getValue</a></li><li><a href="global.html#handleMessageFromWorker">handleMessageFromWorker</a></li><li><a href="global.html#handler">handler</a></li><li><a href="global.html#initialize">initialize</a></li><li><a href="global.html#loadCodecs">loadCodecs</a></li><li><a href="global.html#loadWebWorkerTask">loadWebWorkerTask</a></li><li><a href="global.html#registerLoaders">registerLoaders</a></li><li><a href="global.html#registerTaskHandler">registerTaskHandler</a></li><li><a href="global.html#setPixelDataType">setPixelDataType</a></li><li><a href="global.html#setTaskPriority">setTaskPriority</a></li><li><a href="global.html#spawnWebWorker">spawnWebWorker</a></li><li><a href="global.html#startTaskOnWebWorker">startTaskOnWebWorker</a></li><li><a href="global.html#terminate">terminate</a></li><li><a href="global.html#unpackBinaryFrame">unpackBinaryFrame</a></li></ul>
</nav>
<div id="main">
<h1 class="page-title">shared/decoders/decodeJPEGBaseline8Bit.js</h1>
<section>
<article>
<pre class="prettyprint source linenums"><code>import libjpegTurboFactory from '@cornerstonejs/codec-libjpeg-turbo-8bit/dist/libjpegturbowasm_decode.js';
// Webpack asset/resource copies this to our output folder
import libjpegTurboWasm from '@cornerstonejs/codec-libjpeg-turbo-8bit/dist/libjpegturbowasm_decode.wasm';
const local = {
codec: undefined,
decoder: undefined,
};
function initLibjpegTurbo() {
if (local.codec) {
return Promise.resolve();
}
const libjpegTurboModule = libjpegTurboFactory({
locateFile: (f) => {
if (f.endsWith('.wasm')) {
return libjpegTurboWasm;
}
return f;
},
});
return new Promise((resolve, reject) => {
libjpegTurboModule.then((instance) => {
local.codec = instance;
local.decoder = new instance.JPEGDecoder();
resolve();
}, reject);
});
}
// imageFrame.pixelRepresentation === 1 <-- Signed
/**
*
* @param {*} compressedImageFrame
* @param {object} imageInfo
* @param {boolean} imageInfo.signed -
*/
async function decodeAsync(compressedImageFrame, imageInfo) {
await initLibjpegTurbo();
const decoder = local.decoder;
// get pointer to the source/encoded bit stream buffer in WASM memory
// that can hold the encoded bitstream
const encodedBufferInWASM = decoder.getEncodedBuffer(
compressedImageFrame.length
);
// copy the encoded bitstream into WASM memory buffer
encodedBufferInWASM.set(compressedImageFrame);
// decode it
decoder.decode();
// get information about the decoded image
const frameInfo = decoder.getFrameInfo();
// get the decoded pixels
const decodedPixelsInWASM = decoder.getDecodedBuffer();
const encodedImageInfo = {
columns: frameInfo.width,
rows: frameInfo.height,
bitsPerPixel: frameInfo.bitsPerSample,
signed: imageInfo.signed,
bytesPerPixel: imageInfo.bytesPerPixel,
componentsPerPixel: frameInfo.componentCount,
};
const pixelData = getPixelData(frameInfo, decodedPixelsInWASM);
const encodeOptions = {
frameInfo,
};
return {
...imageInfo,
pixelData,
imageInfo: encodedImageInfo,
encodeOptions,
...encodeOptions,
...encodedImageInfo,
};
}
function getPixelData(frameInfo, decodedBuffer) {
if (frameInfo.isSigned) {
return new Int8Array(
decodedBuffer.buffer,
decodedBuffer.byteOffset,
decodedBuffer.byteLength
);
}
return new Uint8Array(
decodedBuffer.buffer,
decodedBuffer.byteOffset,
decodedBuffer.byteLength
);
}
export default decodeAsync;
</code></pre>
</article>
</section>
</div>
<br class="clear">
<footer>
Documentation generated by <a href="https://github.com/jsdoc3/jsdoc">JSDoc 3.6.7</a> using the <a href="https://github.com/clenemt/docdash">docdash</a> theme.
</footer>
<script>prettyPrint();</script>
<script src="scripts/polyfill.js"></script>
<script src="scripts/linenumber.js"></script>
</body>
</html>