Quanta image sensor (QIS) was introduced as a paradigm shift in image capturing to take advantage of shrinking pixel sizes. The key aspects of the single-bit QIS involve counting individual photoelectrons using tiny, spatially oversampled binary photodetectors at high readout rates, representing this binary output as a bit cube (x,y,t) and finally processing the bit cubes to form high dynamic range images. A QIS may contain over a billion jots, each producing just 1mV/e- of signal, with a field readout rate 10-100 times faster than conventional CMOS image sensors. Use of conventional CMOS imager readout circuits would result in high power dissipation and impact sensor performance. The principal challenge addressed in this talk is the design of internal high-speed and low-power addressing and readout circuitry for QISs.