To improve the adaptive performance of image enhancement,firstly,a kind of adaptivechemotaxis factor of bacteria is employed to the bacterial foraging optimization.Then the improved adaptive bacterial foraging algorithm(ABFA) is combined with the incomplete Beta function to obtainthe optimum grey translation parameters.Finally,the degraded image is enhanced adaptively to theutmost extent.The simulation results show that the improved optimization algorithm is more efficient torefine parameters of the Beta function than its counterpart,which enhances the global contrast of theimage and visual effect.