A perceptive uniform pseudo-color coding method of SAR images

Synthetic aperture radar (SAR) can provide all-time and all-weather surveying of the earth, and SAR images often display in gray scale. Considering the fact that gray scale only has 60 to 90 just noticeable differences (JNDs), while color scale might give up to 500 JNDs, a new pseudo-color coding method based on CIE L*a*b* perceptive uniform color space is introduced for SAR image display. The method is a uniform color space in that equal difference of gray value is approximately equivalent to equal chromatism difference. The primary strongpoint of this method is that it does not generate distortion of SAR image. What´s more, it can include all the information of a gray scale SAR image while improve the visual perception and cognitive ability of SAR image. Also, the Kullback-Leibler (KL) divergence is introduced to evaluate quality of this pseudo-coding method. Three SAR images of different terrain are tested with both CIE L*a*b* perceptive uniform pseudo-color coding method and the mostly commonly used rainbow pseudo-color coding method. Results indicate that the first is superior