Add function to return SVG as JSON Array

README.md

@@ -83,6 +83,7 @@ trace.loadImage('path/to/image.png', function(err) {
 
   trace.getSVG(); // returns SVG document contents
   trace.getPathTag(); // will return just <path> tag
+  trace.getJson(); // returns SVG document contents in JSON format
   trace.getSymbol('traced-image'); // will return <symbol> tag with given ID
 });
 
@@ -181,4 +182,4 @@ The GNU General Public License version 2 (GPLv2). Please see [License File](LICE
 [multilevel-thresholding]: http://www.iis.sinica.edu.tw/page/jise/2001/200109_01.pdf
 [potrace-by-kilobtye]: https://github.com/kilobtye/potrace
 [potrace-js-demo]: http://kilobtye.github.io/potrace/
-[jimp]: https://github.com/oliver-moran/jimp
+[jimp]: https://github.com/oliver-moran/jimp

lib/Potrace.js

@@ -1143,6 +1143,54 @@ Potrace.prototype = {
         : '') +
       '\t' + this.getPathTag(this._params.color, scale) + '\n' +
       '</svg>';
+  },
+
+  /**
+   * Generates a JSON object with path information
+   *
+   * @param {string} [fillColor=auto] - overrides color from parameters
+   * @param {Object} [scale={ x: 1, y: 1 }] - override svg scale
+   * @param {number} [scale.x=1] - scale of the x dimension
+   * @param {number} [scale.y=1] - scale of the y dimension
+   * @param {String} [stroke=none] - override svg stroke value
+   * @param {boolean} [json=false] - return result as a json array of paths
+   * @returns {Array.<object>}
+   */
+  getJson: function(fillColor='auto', scale={ x: 1, y: 1 }, stroke='black') {
+    fillColor = arguments.length === 0 ? this._params.color : fillColor;
+
+    if (fillColor === Potrace.COLOR_AUTO) {
+      fillColor = this._params.blackOnWhite ? 'black' : 'white';
+    }
+
+    if (!this._imageLoaded) {
+      throw new Error('Image should be loaded first');
+    }
+
+    if (!this._processed) {
+      this._bmToPathlist();
+      this._processPath();
+      this._processed = true;
+    }
+
+    const tags = [];
+    tags.push({
+      width: this._params.width || this._luminanceData.width,
+      height: this._params.height || this._luminanceData.height
+    });
+    this._pathlist.forEach(path => {
+      tags.push({
+        d: utils.renderCurve(path.curve, scale),
+        fill: fillColor,
+        stroke: stroke,
+        fillRule: 'evenodd'
+      });
+    });
+    tags.forEach((path, index) => {
+      path.id = index;
+    });
+
+    return tags;
   }
 };
 
@@ -1167,4 +1215,4 @@ module.exports = Potrace;
  * Jimp module
  * @external Jimp
  * @see https://www.npmjs.com/package/jimp
- */
+ */