For the clearness of colored images captured by underwater image sensors, a lαβ color space image clearness algorithm is proposed. On the basis of former dark channel prior algorithm treatment on captured color images, the space mapping is used for further clearness processing, and changing RGB images to lαβ color space images. For the brightness channel l, the Tetrolet transform method is adopted. The bilateral filter is used to filter underwater image noise of high-frequency components, which contains most rough, edges, and other linear details. The nonlocal uniform filter is used to recover the clear low-frequency components, which contains the image’s most energy. Processed high-frequency and low-frequency images are inversely converted by Tetrolet transform to get recovered brightness channel image. The spatial mean color correction method is adopted to get recovered α and β channel images, and the processed brightness channel image and color channel images are inversely transformed to RGB space. Updating the transmissivity by input image to get clear color underwater image. Experimental results show that the proposed algorithm works well on underwater image restoration, and it is effective on the image color promotion and edge description.