A method of histogram incomplete equalization
Changchun Liu · Journal of Shandong University of Technology · 2003
Amending histogram is one of the practical a nd effective methods for imag e enhancement. Because the vision of man responds to the logarithm or the cube r oot of image lightness approximately, over-bright phenomenon appears in the hig h gray area of the image treated by traditional histogram equalization. A new met hod of histogram equalization named histogram incomplete equalizati on is presented to accomplish the traditional histogram equalization treatment in the low gray area and achieve gray transform according to the reciprocal orderlines s with the vision of man in the high gray area of image processing. A concept of the high gray area threshold r δ for histogram incomplete equ alization is introduced and the calculation formula of its optimal value is de rived. This method can also compen sate the over-bright phenomenon in high gray area of the image treated by the general histogram equalization effectively.