draw an image in a picture

Titanium SDK 3.4.0 for IOS an Android

Hello,

I want to put a logo in the bottom right of a picture and save it. I don't want to show it, just want to take the picture, draw the logo and save.

I know how to save the picture.

module.exports = {
    init: function(){},
    start: function(win){
        Titanium.Media.showCamera({
            success:function(e) {
                if (e.mediaType == Ti.Media.MEDIA_TYPE_PHOTO) {
                    var img = e.media;
                    //change the image
                }
            },
            cancel:function() {
            },
            error:function(error) {
            },
            saveToPhotoGallery:true,
            allowEditing:true,
            mediaTypes:[Ti.Media.MEDIA_TYPE_VIDEO,Ti.Media.MEDIA_TYPE_PHOTO]
        });
    }
};