液晶顯示器之對比加強,銳利度加強及色溫調整

Abstract

在現今資訊顯示的應用上, 液晶顯示器(LCD display)日益普及.液晶螢幕具有體積小, 重量輕, 耗電低, 無閃爍等優點. 小至行動電話, 個人行動助理(PDA)的液晶顯示面板, 大至電腦系統的監視器(monitor)及大尺寸的液晶電視, 液晶顯示器無所不在. 然而就色彩上及影像品質上的表現, 則仍有遜於傳統CRT顯示器. 本論文欲針對液晶螢幕, 研發相關影像品質加強的演算法. 其中包含了對比加強, 銳利度加強和色溫轉換. 在對比加強中, 我們首先攫取影像邊角資訊, 並運用此資訊產生相對的擴張力進行影像對比加強的處理. 在銳利度加強中, 我們發展出一套依據人眼視覺特性為基礎的加強方式. 最後, 色溫轉換的部分, 我們提出一套根據傳統灰世界理論為基礎的色溫估測方式, 根據所估測的色溫資訊及色溫轉換機制, 以達到影像色溫轉換的目的.

Nowadays, liquid crystal display (LCD) has become one of the most popular electronic products in consumer electronics. LCD’s have been widely used in mobile phones, personal digital assistants (PDA), and TV’s. Advantages of LCD’s include low power consumption, light weight, lower radiation, and so on. However, due to some physical limitations of liquid crystal, the quality of displayed images on LCD’s is inferior to that on cathode ray tubes (CRT). In this thesis, we aim to construct some image processing techniques for LCD. These techniques include contrast enhancement, sharpness enhancement and color temperature adjustment. About contrast enhancement, the edge information of the image is used and a corresponding expansion force is generated to enhance contrast. For sharpness enhancement, we propose a new approach for enhancement based on some characteristics of human visual perception. For color temperature adjustment, we propose a new approach for color temperature estimation based on gray world assumption.