konva/src/filters/Invert.js

<p align="center"> <img src="https://raw.githubusercontent.com/konvajs/konvajs.github.io/master/apple-touch-icon-180x180.png" alt="Konva logo" height="180" /> </p>

(function() {
  'use strict';
  /**
    * Invert Filter
    * @function
    * @memberof Konva.Filters
    * @param {Object} imageData
    * @example
    * node.cache();
    * node.filters([Konva.Filters.Invert]);
    */
  Konva.Filters.Invert = function(imageData) {
    var data = imageData.data, len = data.length, i;

    for (i = 0; i < len; i += 4) {
      // red
      data[i] = 255 - data[i];
      // green
      data[i + 1] = 255 - data[i + 1];
      // blue
      data[i + 2] = 255 - data[i + 2];
    }
  };
})();