1. A calibration system for stereo cameras, the calibration system comprising: a rig control module configured to perform physical calibration for a camera based on a camera calibration parameter by controlling an auto rig according to the camera calibration parameter; a stereo image calibration apparatus configured to calibrate a stereo image to acquire the camera calibration parameter, and output the acquired camera calibration parameter; and a camera control module configured to output the camera calibration parameter, which is input from the stereo image calibration apparatus, to the rig control module, or screen-output the camera calibration parameter, wherein the stereo image calibration apparatus comprises: a stereo color calibration module configured to perform color calibration for the stereo image; and a geometry calibration module configured to perform geometry calibration for the color-calibrated stereo image to generate a rectification stereo image, and analyze the generated rectification stereo image to acquire the camera calibration parameter.