Abstract: In order to restore the degraded images collected by outdoor acquisition devices in haze weather，this paper proposes an image defogging system on the MATLAB platform. The system can restore foggy degradation images to different degrees through four classic defogging algorithms：global histogram equalization，local histogram equalization，multiscale Retinex，and dark channel prior. The defogging effects are compared by image quality evaluation indicators. Experimental results show that the sharpness and contrast of the images processed by different defogging algorithms have been improved， and the corresponding algorithm can be selected according to the needs of the scene in practical applications. The implement of the system lays a foundation for the research of image defogging technology，and it has good operability.

Key words: MATLAB, image defogging system, image quality evaluation