pinchgesture and two image zoom

I have one image 768 x 1024 size. second image is on that image at x=50 and y=100 with height of 30 and width of 1024.

when i stretch first image second image stays as it is.

I want what ever part is hidden by secon开发者_运维百科d image to stay hidden as when i stretch image. basically when i zoom first image second image will also zoomed.

how can i do so?

if we want to zoom as this way add this two image on view and zoom that view. Scalefactor at after zoom will as same as before zoom.