Some existing enhancement methods enhance uneven lighting images by bringing out the details in the dark areas， but easily result in over-enhancement. In this paper， an extended form of Retinex is proposed from a new viewpoint and applied to uneven lighting image enhancement. Taking the center-surround Retinex output as the perceived reflectance， the proposed algorithm decomposes an image into a perceived reflectance image and a perceived illumination one. Image enhancement can be achieved by adjusting the perceived illumination image and combining back both images. Experimental comparisons with some state-of the-art methods show that the proposed method has good performance on enhancing brightness and details， and improving the image quality for uneven lighting images.