一個應用於數位影像感測器的混合式顏色還原法

Color Filter Array Interpolation Using a Hybrid Method

李俊豪(ChunHao Lee)

指導教授 ： 林啟芳

元智大學/資訊學院/資訊工程學系/碩士(2004年)

摘要

近幾年來數位相機越來越普及，已逐漸取代傳統使用軟片的相機。為了降低成本和縮小尺寸，大部分廠商皆使用單一晶片影像感測器CCD或CMOS來捕捉影像，大多數影像感測器皆採用一種叫做 Bayer pattern的資料格式，因每個像點只取一種顏色，所以需將影像顏色還原回全彩，此種還原的技術我們稱為CFA內插法(CFA interpolation)或解馬賽克法(Demosaicing)。此種技術一直存有兩種主要的問題需要去克服，一是假色問題，另一個是鋸齒現象問題，這些問題皆因使用錯誤的像點還原所造成。本論文提出一個混合式的方法來還原顏色，此方法主要分兩步驟：第一步為顏色還原處理，使用數種 CFA 內插法混合而成的方法來還原顏色。和第二步為顏色校正處理，使用改良式的中間值濾波法來校正顏色還原處理的顏色。從實驗結果得知我們的混合式方法可有效的提昇影像還原品質和降低假色與鋸齒現象的程度。

關鍵字

數位相機 ； 影像感測器 ； 解馬賽克

並列摘要

Most digital still cameras capture the natural image using sensors of charge coupled device(CCD) or complementary metal oxide semiconductor (CMOS). The surface of the sensor is usually covered with a color filter array(CFA). In this arrangement, only one color sample is taken for each pixel, and the values of the other colors must be estimated from the neighboring pixels. This process is called the demosaicing process, or the CFA interpolation. In this paper, we propose a new demosaicing method that consists of two steps: an interpolation step that reconstructs to full color by a hybrid method, and a post-processing step that suppresses noticeable demosaicing artifacts by adaptive median filtering. Experimental results will show the proposed method has better perceptual quality as compared to the other published methods.

並列關鍵字

Demosaicing ； CFA interpolation ； Color Filter Array

參考文獻

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