Hi Guys,
Why use OV7670, it outputs uncompressed image, that is really to large for Arduino to handle.
You can try other image sensors from Omnivision like OV2640, OV3640 ,OV5642 which can output compressed JPEG image. And the output data is really small than OV7670.
You can take a look at OV5642 camera module sample pictures from 5MP: OV5642 - Arducam