Gstreamer get image width and height

Question

I have a simple gstreamer pipeline which looks like :

| Filesrc | --> | PngDec | --> | ImageFreeze | --> | Queue | --> | Compositor | --> | Fake Sink |

location (input) of the filesrc is a png file of size 400 X 600.

In the pipeline how do I get the width and height of the file? (400 X 600)