image-sequencer/src/modules/Resize/Module.js

/*
 * Resize the image by given percentage value
 */
module.exports = function Resize(options, UI) {

  var output;

  function draw(input, callback, progressObj) {

    var defaults = require('./../../util/getDefaults.js')(require('./info.json'));
    options.resize = options.resize || defaults.resize;

    progressObj.stop(true);
    progressObj.overrideFlag = true;

    var step = this;

    var imagejs = require('imagejs');

    function changePixel(r, g, b, a) {
      return [r, g, b, a];
    }

    function extraManipulation(pixels) {
      // value above 100% scales up, and below 100% scales down
      var resize_value = parseInt(options.resize.slice(0, -1));

      var new_width,
        new_height;

      new_width = Math.round(pixels.shape[0] * (resize_value / 100));
      new_height = Math.round(pixels.shape[1] * (resize_value / 100));

      var bitmap = new imagejs.Bitmap({width: pixels.shape[0], height: pixels.shape[1]});
      bitmap._data.data = pixels.data;


      var resized = bitmap.resize({
        width: new_width, height: new_height,
        algorithm: 'bicubicInterpolation'
      });

      pixels.data = resized._data.data;
      pixels.shape = [new_width,new_height,4];
      pixels.stride[1] = 4 * new_width;

      return pixels;
    }

    function output(image, datauri, mimetype) {
      // This output is accesible by Image Sequencer
      step.output = { src: datauri, format: mimetype };
    }

    return require('../_nomodule/PixelManipulation.js')(input, {
      output: output,
      changePixel: changePixel,
      extraManipulation: extraManipulation,
      format: input.format,
      image: options.image,
      inBrowser: options.inBrowser,
      callback: callback
    });
  }

  return {
    options: options,
    draw: draw,
    output: output,
    UI: UI
  };
};