display, adjust, & combine 2 images with javascript

I want to create an application where it can display two images, first image is a face image from user and the second is the nose image that is available to 开发者_如何学JAVAchoose to be matched with the face. So when i upload face images, i can choose the matching nose and adjust position, size etc.. then merge them into one image. I want to create with JavaScript and maybe merge them into one using php function, I still confuse where should I start.

Any idea? reference? Thank all

A tutorial for Overlapping Images in php using GD:

Overlapping Images with GD (part 1)

Overlapping Images with GD (part 2)

Overlapping Images with GD (part 3)

other functions to upload images and showing them and handling some user user friendly actions can be done easily with javascript. if there was any question in these parts, I can help.