基於整數型態之色彩插補演算法設計

Design of Integer-Based Color Interpolation

張明凱(M. K.. Chang)

指導教授 ： 蘇崇彥

國立臺灣師範大學/科技學院/應用電子科技研究所/碩士(2011年)

摘要

近年來，大多數消費型數位相機為了減少體積與製作成本，採用前方覆蓋一層彩色濾波陣列(Color Filter Array)的感光元件。而由於CFA的結構，將造成各個像素點僅能擷取到光的三原色(紅、綠、藍)其中之一的資訊。色彩插補演算法的目的在即於藉由鄰近像素點的顏色資訊估測各像素點上所失去的另外兩種顏色，達到還原真實影像的效果。
目前有許多的色彩插補演算法被提出，雖然在逐年的發展之下，影像還原已有相當不錯的品質，但在計算複雜度與影像品質間仍然無法取得令人滿意的結果。因此，本篇論文提出一種整數型態的插補演算法，在降低計算複雜度後還能保有一定的影像還原品質。本文提出的方法主要特點為利用理想整數濾波器來插補綠色以及使用包含方向之雙線性濾波器進一步提升插補後的品質。期望藉由本文提出的低複雜度的演算法能提高被實作的可能性。
實驗方面我們使用柯達24張圖片做測試，並分別以數據和視覺評估的方式做比較。實驗結果證實，本文提出的整數型態的演算法能有效的減少執行時間且在主觀的視覺上也能得到不錯的效果。

關鍵字

色彩插補 ； 解馬賽克 ； 貝爾圖形 ； 整數型態 ； 數位相機

並列摘要

Most commercial digital still cameras use a single sensor (e.g., CMOS or CCD) with a color filter array(CFA) to reduce the product size and cost. Since the CFA structure, only one of the three primary colors is obtained at each pixel location and the other two are missing. The aim of color interpolation is to estimate the other two missing color values by neighboring pixels. Recently many color interpolation algorithm have been proposed, but most of them can not satisfy the needs of low computational complexity and high reconstructed image quality at the same time. In addition, few of them are suitable for the implementation by integer processors. To solve above problems, we present an effective integer color interpolation algorithm. The novelties of the proposed algorithm include an optimal integer FIR filter and a new directional refining step. Experimental results verify the effectiveness of the proposed algorithm and show that it outperforms several existing integer techniques.

並列關鍵字

Demosaicing ； Color Interpolation ； Integer-Based method ； Bayer pattern ； Digital camera

參考文獻

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