1. An image sensor, comprising: a Complementary Metal Oxide Semiconductor (CMOS) photosensitive array, a row selection circuit, a column selection circuit and a control signal conversion circuit, wherein the CMOS photosensitive array is adapted for converting optical signals to electrical signals; wherein the control signal conversion circuit is adapted for converting a first set of control signals to a second set of control signals, the first set of control signals are adapted for driving a Charge-Coupled Device (CCD) photosensitive array and comprise at least a vertical transfer signal, a horizontal transfer signal, an electronic shutter signal and a readout clock signal, and the second set of control signals comprises at least a column address signal, a row reset control signal and a row readout control signal; wherein the row selection circuit is adapted for receiving the row reset control signal and the row readout control signal, generating a row reset signal according to the row reset control signal, and generating a row readout signal according to the row readout control signal, wherein the row reset signal is adapted for controlling a reset operation of each row of the CMOS photosensitive array, and the row readout signal is adapted for controlling a readout operation of each row of the CMOS photosensitive array; and wherein the column selection circuit is adapted for receiving the column address signal, performing a column strobe operation on the CMOS photosensitive array under control of the column address signal, and outputting a column readout signal.