voluptasquisquam/src/browser/worker/process/background.js

Image processing and manipulation in JavaScript

import extend from 'extend';
import Image from '../../../image/Image';

const defaultOptions = {
    regression: {
        kernelType: 'polynomial',
        kernelOptions: {degree: 2, constant: 1}
    },
    threshold: 0.02,
    roi: {
        minSurface: 100,
        positive: false
    },
    sampling: 20,
    include: []
};

function run(image, options, onStep) {
    options = extend({}, defaultOptions, options);
    const manager = this.manager;
    if (Array.isArray(image)) {
        return Promise.all(image.map(function (img) {
            const run = runOnce(manager, img, options);
            if (typeof onStep === 'function') {
                run.then(onStep);
            }
            return run;
        }));
    } else {
        return runOnce(manager, image, options);
    }
}

function runOnce(manager, image, options) {
    return manager.post('data', [image, options]).then(function (response) {
        for (let i in response) {
            response[i] = new Image(response[i]);
        }
        return response;
    });
}

function work() {
    worker.on('data', function (send, image, options) {
        image = new IJS(image);
        const result = {};
        const toTransfer = [];

        const grey = image.grey();

        const sobel = grey.sobelFilter();
        maybeInclude('sobel', sobel);

        const mask = sobel.level().mask({threshold: options.threshold});
        maybeInclude('mask', mask);

        const roiManager = sobel.getRoiManager();
        roiManager.fromMask(mask);
        const realMask = roiManager.getMask(options.roi);
        maybeInclude('realMask', realMask);

        const pixels = grey.getPixelsGrid({
            sampling: options.sampling,
            mask: realMask
        });

        const background = image.getBackground(pixels.xyS, pixels.zS, options.regression);
        maybeInclude('background', background);

        const corrected = image.subtract(background);

        result.result = corrected;
        toTransfer.push(corrected.data.buffer);
        send(result, toTransfer);

        function maybeInclude(name, image) {
            if (options.include.includes(name)) {
                result[name] = image;
                toTransfer.push(image.data.buffer);
            }
        }
    });
}

export default {run, work};