1.7~3.0V is the standard voltage range.
The absolute maxium voltage is 4.5V for Vio.
And in fact, as a highspeed signal, the voltage will attenuated though the lines.
It will drop to less than 2.8V (as I saw in oscilloscope).
In the other hand, PE0 & PE1 is for DVP camera, what I provide is OV2640. (OV5647 is provided as MIPI camera )
OV2640's Vio is 1.7~3.3V.
Don't be worried about camera, they are robust enough ^_^