image-filter-threshold

    2.0.1 • Public • Published

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    image-filter-threshold

    Small library to apply a threshold transformation to a image relying on image-filter-core handle the transformation and distribute work with webworkers.

    Other related modules:

    Install

    npm install image-filter-threshold --save
    

    Usage

    It applies a threshold transformation to a base64 image. If you want a more complete library, please check image-filters that wraps this and other libraries to provide a more complete suite of image filters.

    This library consumes ImageData and outputs ImageData in a Promise. You can use image-filter-core to convert from ImageData to dataURL.

    JS file:

    var imageThreshold = require('image-threshold');
    var nWorkers = 4;
     
    imageThreshold(IMAGE_DATA, { threshold: 30 }, nWorkers);

    Frequent questions:

    How can I get image data from a image tag?

    var element = document.getElementById('#dummy-image');
    var canvas = document.createElement('canvas');
    var context = canvas.getContext('2d');
    context.drawImage(element, 0, 0 );
    var imageData = context.getImageData(0, 0, element.width, element.height);

    How can I get image data from url?

    var element = document.createElement('img');
    element.setAttribute('src', options.url);
    //...repeat process from the previous answer

    How can I use the output of this?

    var imageFilterCore = require('image-filter-core');
    var nWorkers = 4;
     
    imageThreshold(IMAGE_DATA, { threshold: 30 }, nWorkers)
        .then(function (result) {
            // result === ImageData object
            var image = document.createElement('img');
            image.setAttribute('src', imageFilterCore.convertImageDataToCanvasURL(imageData));
            target.appendChild(image);
        });

    Install

    npm i image-filter-threshold

    DownloadsWeekly Downloads

    100

    Version

    2.0.1

    License

    ISC

    Last publish

    Collaborators

    • canastro