A simple way of panning and zooming an image using Hammer.js.

pan-zoom-image.js

// <img id="myimage" src="http://placecage/1280/720">
var image = document.getElementById('myimage');

var mc = new Hammer.Manager(image);

var pinch = new Hammer.Pinch();
var pan = new Hammer.Pan();

pinch.recognizeWith(pan);

mc.add([pinch, pan]);

var adjustScale = 1;
var adjustDeltaX = 0;
var adjustDeltaY = 0;

var currentScale = null;
var currentDeltaX = null;
var currentDeltaY = null;

// Prevent long press saving on mobiles.
webpage.addEventListener('touchstart', function (e) {
    e.preventDefault()
});

// Handles pinch and pan events/transforming at the same time;
mc.on("pinch pan", function (ev) {

    var transforms = [];

    // Adjusting the current pinch/pan event properties using the previous ones set when they finished touching
    currentScale = adjustScale * ev.scale;
    currentDeltaX = adjustDeltaX + (ev.deltaX / currentScale);
    currentDeltaY = adjustDeltaY + (ev.deltaY / currentScale);

    // Concatinating and applying parameters.
    transforms.push('scale({0})'.format(currentScale));
    transforms.push('translate({0}px,{1}px)'.format(currentDeltaX, currentDeltaY));
    webpage.style.transform = transforms.join(' ');

});


mc.on("panend pinchend", function (ev) {

    // Saving the final transforms for adjustment next time the user interacts.
    adjustScale = currentScale;
    adjustDeltaX = currentDeltaX;
    adjustDeltaY = currentDeltaY;

});

I solved and also posted an answer on Stackoverflow to an user who experienced my same problem. I discovered that console said that the mc.get() returned a null value. As a matter of fact, with my above statements, the mc object.recognizers array was void.
So I used this way to initializate the hammer instance:
var mc = new Hammer.Manager(myElement, { recognizers: [ [Hammer.Pinch, {enable: false}] ] });
and now it works.

Why should recognize pinch and pan? and in my config, the pinch event will always trigger the pan event, This really bother me.

Maybe somebody knows packages where it is implemented?