Due　to　the　phenomenon　of　contact　angle　saturation　and　charge　trapping,　contrast　of　the　electrowetting　display　will　be　decreased,　and　the　details　of　the　image　will　be　lost.　A　histogram　equalization　algorithm　is　commonly　used　to　improve　the　image　contrast　enhancement.　Therefore,　in　order　to　improve　the　display　quality　of　the　electrowetting　display,　this　article　proposes　an　extension　of　dynamic　histogram　equalization　(DHE)　techniques,　called　intensity　preservation-based　dynamic　histogram　equalization　(IPDHE).　Initially,　the　proposed　IPDHE　technique　separates　the　histogram　into　four　subhistograms　based　on　intensity　preservation.　Then,　the　resultant　subhistograms　are　reshaped　by　the　nonzero　bins　as　the　amount　of　emphasis　given　on　total　pixels.　Mathematically,　the　intensity　preservation　measure　of　each　subhistogram　stands　for　the　density　and　boosted　level　of　the　subhistogram.　Finally,　each　subhistogram　is　equalized.　Simulation　results　show　that,　for　the　dataset　of　test　images,　the　proposed　algorithm　successfully　enhances　the　contrast　of　images　while　preserving　the　maximum　average　information　content　(entropy),　presents　more　image　details,　and　applies　to　the　electrowetting　display.　©　2019　Institute　of　Electrical　Engineers　of　Japan.　Published　by　John　Wiley　&　Sons,　Inc.　©　2019　Institute　of　Electrical　Engineers　of　Japan.　Published　by　John　Wiley　&　Sons,　Inc.