ial gital ce, on. al 003 Abstract. Many different descriptions of Retinex methods of lightness computation exist. We provide concise MATLABTM implementations of two of the spatial techniques of making pixel comparisons. The code is presented, along with test results on several images and a discussion of the results. We also discuss the calibration of input images and the postRetinex processing required to display the output images. © 2004 SPIE and IS&T. [DOI: 10.1117/1.1636761]