How can i achieve such an animation

Hi.

I have a sample here.

You can of course improve the transition between the two images. It's just a matter of modifying the anim Movie Clip instance. The code will remain the same.

Preview:

Live demo:

index

JS:

var root = this;
var slider = root.slider;
var button = slider.button;
var bar = slider.bar;
button.mouseDownHandler = function(e)
{
    // we need to get the difference from the mouse y coordinate to the origin of the button instance and also taking into account the stage scale
    this.offsetY = (e.stageY / stage.scaleY) - this.y;
};
button.pressMoveHandler = function(e)
{
    var scrollHeight = bar.nominalBounds.height - button.nominalBounds.height;
    this.y = (e.stageY / stage.scaleY) - this.offsetY;
    this.y = root.clamp(this.y, this.nominalBounds.y, scrollHeight);
    // the y coordinate of the button divided by the scroll height gives a value from 0 to 1. Then we multiply it by the total frames we have in the animation Movie Clip instance. The result must be rounded.
    root.anim.gotoAndStop(Math.round(root.anim.totalFrames * (this.y / scrollHeight)));
};
// limits a value within a range
root.clamp = function(value, min, max)
{
    if (value < min)
          return min;
    if (value > max)
          return max;
    return value;
};
root.start = function()
{
    document.body.style.backgroundColor = lib.properties.color; // sets the background color for the page
    createjs.Touch.enable(stage); // enables touch interaction for the default stage
    stage.mouseMoveOutside = true; // mouse move events will continue to be called when the mouse leaves the target canvas
    stage.preventSelection = true; // prevents selection of other elements in the html page if the user clicks and drags
    root.anim.loop = false; // it prevents a Movie Clip instance from returning to the first frame when the last frame is reached
    button.on("mousedown", button.mouseDownHandler);
    button.on("pressmove", button.pressMoveHandler);
};
root.start();

FLA download:

animate_cc_html5_canvas_drag_to_reveal.zip - Google Drive

I hope this helps.

Regards,

JC