Image sensor and camera system having the same

A camera system where an image sensor chip and a driving chip are integrated as a system on chip (SOC), the image sensor chip comprising:

• a pixel array having a plurality of unit pixels with high light sensitivity, for sensing information about image received from an exterior;
• a control and interface means for controlling an overall operation of an image sensor chip and acting as an interface with an external system;
• an analog signal processing means for processing an analog signal from the pixel array after being controlled by the control and the interface means;
• an analog to digital (A/D) converter for converting the analog signal into a digital signal;
• a picture signal processing means for performing a plurality of image processes in order to enhance image of the digital signal, wherein the picture signal processing means includes a focus value calculator for calculating a focus value from the digital signal;
• and
• an interface means for providing an exterior with the focus value calculated through the focus value calculator.