OV7670 with SD Card

I have googled a lot, but I don't seem to find anything that helps me with my situation.

I have an OV7670 camera, Arduino Uno/Mega and an ethernet shield to hold the SD card. I also have a ROBOT LCD Arduino screen which also takes an SD card.

I would like to be able to take a picture every 6 hours and save it on the SD card (preferably with the ethernet shield).

Can anyone please help me with this?

I have found multiple threads each specifying a different way of connecting the camera to the Arduino, but none seem to be what I want.

Thank you