Histogram equalization is widely used for contrast

enhancement in a variety of applications due to its

simple function and effectiveness. Examples include

medical image processing and radar signal process-

ing. One drawback of the histogram equalization can

be found on the fact that the brightness of an im-

age can be changed after the histogram equalization,

which is mainly due to the flattening property of the

histogram equalization. Thus, it is rarely utilized in

consumer electronic products such as TV where pre-

serving original input brightness may necessary in or-

der not to introduce unnecessary visual deterioration.

This paper proposes a novel extension of histogram

equalization to overcome such drawback of the his-

togram equalization. -Histogram　equalization　is　widely used　for　contrast

enhancement in　a　variety　of　applications due　to　its

simple function　and　effectiveness.　Examples　include

medical　image　processing　and　radar　signal　process-

ing. One drawback of　the histogram equalization can

be　found on　the　fact　that　the　brightness　of　an　im-

age can be　changed　after　the histogram equalization,

which　is mainly due　to the flattening property　of　the

histogram　equalization.　Thus, it　is rarely　utilized　in

consumer electronic products　such as TV where pre-

serving original input brightness may necessary　in or-

der not　to introduce unnecessary　visual deterioration.

This paper　proposes　a　novel　extension　of　histogram

equalization　to overcome such　drawback　of　the　his-

togram　equalization.