PIXON analyzes reverberation mapping in active galactic nuclei. The pixon method uses pixons (instead of pixels) as the basic unit, which are able to adjust pixon sizes to achieve locally optimal resolutions according to the information content provided by the data. Within a pixon, the pixon algorithm smooths the solutions as much as the data allow. The terminated criterion of the pixon method is to find the fewest number of pixons that still adequately fit the data. As such, the pixon method optimizes solutions not only by testing the goodness of fit but also by reducing the complexity to be optimal. The issue of overresolution or underresolution of the solutions is also significantly alleviated.