How can I apply a watermark in images using JavaScript? -

i'm using angularjs , need apply watermark programatelly in images calling js function. have is:

<figure><img class="watermark" ng-src="{{applywatermark(img.url)}}"></figure>   

so, need call function applywatermark (not implemented yet) , return img watermark, i'm not sure how can build function. should return image? can provide me example how can this?

edit:

i did this, it's not working:

 $(function applywatermark(image) {                                                                                                                                                                                                            watermark([image, 'watermark.png'])                                                                                                                               .image(watermark.image.lowerright())                                                                                                                                                                                                      .then(function (img) {                                                                                                                                                                                                                        return img                                                                                                                                                                                                                            });                                                                                                                                                                                                                                 })   

any idea?

using watermark.js:

watermark(['/img/forest.jpg', '/img/logo.png'])     .image(watermark.image.lowerright(0.5)) // or lowerright() no opacity     .then(function (img) {         document.getelementbyid('alpha-image').appendchild(img);     }); 

if doesn't work you, maybe try this:

$.ajax({     url: 'http://www.example.com/your-image.jpg',     type: 'head',     error: function() {         // file isn't found     },     success: function() {         // file found! watermarkage.     } }); 

to test if image exists before processing.