The implementation of image contrast reversal by using a photochromicmaterial of Bacteriorhodopsin (BR) films is demonstrated with twomethods based on the optical properties of BR. One is based on theabsorption difference between the B and M states. Images recorded bygreen light can be contrast reversed readout by violet light. The otheris based on the photoinduced anisotropy of BR when it is excited bylinear polarization light. By placing the BR film between two crossedpolarizers (i.e. a polarizer and an analyser), the difference ofpolarization states of the recorded area and the unrecorded area can bedetected, and thus different contrast images can be obtained byrotating the polarization axis of the analyser.