This plug-in can easily convert any colored image into a B&W greyscale image. It uses the the HTML5 canvas tag and a fallback for the old browsers

Usage

1 Include the plug into the page:

<script src="js/jQuery.BlackAndWhite.js"></script>

2 Set the image wrappers using the css:

.bwWrapper {
    position:relative;
    display:block;
}

3 Initialize the plug in on window load (no $(document).ready()):

$(window).load(function(){
    $('.bwWrapper').BlackAndWhite({
        hoverEffect : true, // default true
        // set the path to BnWWorker.js for a superfast implementation
        webworkerPath : false,
        // for the images with a fluid width and height 
        responsive:true,
        // to invert the hover effect
        invertHoverEffect: false,
        speed: { //this property could also be just speed: value for both fadeIn and fadeOut
            fadeIn: 200, // 200ms for fadeIn animations
            fadeOut: 800 // 800ms for fadeOut animations
        }
    });
});

The article source:http://gianlucaguarini.com/canvas-experiments/jQuery.BlackAndWhite/