How to compose a new picture of picture 1 and picture 2

Dispatch_group_notify (group, queue, ^{

1. Turn on the new graphics context

Uigraphicsbeginimagecontext (Cgsizemake (100, 100));

2. Drawing pictures

[Self.image1 drawinrect:cgrectmake (0, 0, 50, 100)];

[Self.image2 Drawinrect:cgrectmake (50, 0, 50, 100)];

3. Get the picture in context

UIImage *image = Uigraphicsgetimagefromcurrentimagecontext ();

4. End Context

Uigraphicsendimagecontext ();

Back to main thread display picture

Dispatch_async (Dispatch_get_main_queue (), ^{

Show a new picture

Self.imageView.image = image;

});

});

How to compose a new picture of picture 1 and picture 2