Package Exports

node-resemble-js

This package does not declare an exports field, so the exports above have been automatically detected and optimized by JSPM instead. If any package subpath is missing, it is recommended to post an issue to the original package (node-resemble-js) to support the "exports" field. If that is not possible, create a JSPM override to customize the exports field for this package.

Readme

node-resemble.js

Analyse and compare images with Javascript. This project does not need canvas or any other binary denpendencies. It is a modification of Resemble.js

Get it

npm install node-resemble-js

Example

Retrieve basic analysis on image.

var api = resemble(fileData).onComplete(function(data){
    console.log(data);
    /*
    {
      red: 255,
      green: 255,
      blue: 255,
      brightness: 255
    }
    */
});

Use resemble to compare two images.

var diff = resemble(file).compareTo(file2).ignoreColors().onComplete(function(data){
    console.log(data);
    /*
    {
      misMatchPercentage : 100, // %
      isSameDimensions: true, // or false
      dimensionDifference: { width: 0, height: -1 }, // defined if dimensions are not the same
      getImageDataUrl: function(){}
    }
    */
});

You can also change the comparison method after the first analysis.

// diff.ignoreNothing();
// diff.ignoreColors();
diff.ignoreAntialiasing();

And change the output display style.

resemble.outputSettings({
  errorColor: {
    red: 255,
    green: 0,
    blue: 255
  },
  errorType: 'movement',
  transparency: 0.3
});
// resembleControl.repaint();

Example usuage (in cucumber step definition)

 this.Then(/^Screenshot should match image "(.*)"$/, function (image, callback) {
    browser.takeScreenshot().then(function(pngString) {
      var screenshot = new Buffer(pngString, 'base64');
 
      resemble(image)
        .compareTo(screenshot)
        .onComplete(function(data){
 
          if (Number(data.misMatchPercentage) <= 0.01) {
            callback();
          } else {
            data.getDiffImage().pack().pipe(fs.createWriteStream(image + 'diff.png'));
            callback.fail(new Error("Screenshot '" + image+  "' differ " + data.misMatchPercentage + "%"));
          }
        });
    });
  })

Credits:

Created by James Cryer and the Huddle development team.
Lukas Svoboda - modification for node.js