In view of histogram equalization regarded as typical ill-posed problem

the adjustable histogram equalization method is explaned by regularization theory

and its improvement is proposed in order to obtain the better effect of image enhancement.Firstly

the objective function of adjustable histogram equalization method is simplified and explaned by means of information energy as a regular item.Secondly

in consideration of the dual relationship between information entropy and information energy

the new adjustable histogram!equalization model based on information entropy as regularization is obtained.Thirdly

the regular item coefficient choosing method of adjustable histogram equalization is presented by means of information entropy or energy of gray levels probability distribution.Finally

the adjustable histogram equalization improvement method based on modifying cumulative probability of gray levels is proposed in order to improve the image enhancement effect of traditional histogram equalization method.Experimental results show that the improvement method of adjustable histogram equalization is effective.