I want to Find the Phase shift of the interference Hologram with Optical Fiber and Slide

I have used an Optical Fiberand a think Slide as the Object in a Holography Microscopy. I need to find the Phase Shfit in the image which i got in on CMOS Camera. so by getting phase shift , i can find the thickness of the Objects using the wavelength. I am new to the Matlab Community. Can anyone Help me for the Same. I will be attaching the images that i need to find the Phase Shifts.