Zoom in and out feature

For ActionScript you could read articles like this one:

Flash Mouse Wheel Support | Hook - Labs

For HTML5 Canvas, here's what @klad suggested in another post:

document.getElementById('canvas').addEventListener('mousewheel',f.bind(this));

document.getElementById('canvas').addEventListener('DOMMouseScroll',f.bind(this));

function f(e){

//e.detail

}

Exactly like that it's not the whole answer, there is wheelDeltaY, so this will give you a useful number about how quickly the user was wheeling:

document.getElementById('canvas').addEventListener('mousewheel',f.bind(this));

document.getElementById('canvas').addEventListener('DOMMouseScroll',f.bind(this));

function f(e){

   alert(e.wheelDeltaY);

}

But, read articles like this about how that only works in some browsers, and for other approaches:

mousewheel - Event reference | MDN

Once you have a usable value you would then need more code to sensibly scale the image.