OV7670 writing to registers

Other Hardware Sensors
4

I think you have missed an end transmission from the write, try these two functions:-

void Write()
{
   Wire.beginTransmission(slaveaddress);
   Wire.write(regaddress);
   Wire.write(regdata);
   Wire.endTransmission();    // stop transmitting
}

void Read()
{
  Wire.beginTransmission(slaveaddress);
   Wire.write(regaddress);
   Wire.endTransmission();
   Wire.requestFrom(regaddress,1);
   int c = Wire.read();   
   Serial.println(c);
}