即時色彩校正硬體架構

本論文的硬體架構如圖6.7所示，用CMOS影像感測器拍攝影像，將影像經由S-Video傳輸到FPGA，再經由FPGA運算完後，再經由DVI傳送到螢幕，實際架構圖如圖 6.8。

圖6.7 FPGA硬體架構圖

圖6.8 FPGA實際架構圖

第 七 章

結 論 與 未 來 展 望

7.1 結論

本論文為內視鏡之色彩影像校正，利用環場式膠囊內視鏡進行腸道假體拍攝，將 腸道假體影像進行重建，但是受到環場式膠囊內視鏡的錐狀鏡機構影響，造成影像接 合時產生不連續問題，本論文採用平均加權平滑法與最佳化縫隙法減少縫隙的產生，

由未改善的峰值訊號雜訊比17.56改善至35.82。

內視鏡與環場式膠囊內視鏡進行色票拍攝，將拍攝到的色票儲存於電腦中，利用 Matlab軟體計算出色度圖與色票所定義的色度圖比較，可以發現到色票所定義的資訊 與所拍攝到的色票影像有所不同，代表著內視鏡受到影像感測器、光源與機構而造成 影像色偏。色票所定義的D65燈源下拍攝色票，由色度圖可以察覺白色色點位置並不相 同，是因受到影像感測器的色彩濾光片影響，造成所拍攝到色彩資訊不相同，接著利 用將燈源更換為LED燈源進行拍攝，由色度圖上可發現並不相同，由此可以推估色彩 資訊也會受到燈源不同所影響，故需將所拍攝的色彩資訊校正至正確位置；再者環場 式膠囊內視鏡因受到膠囊殼影響造成影像偏黃，造成環場式膠囊內視鏡所拍攝影像與 原始色票所定義色彩色差為21.448，利用係數法與複數映射轉換多項式法，分別可以將 色差值降為1.539與1.324，最後將演算法利用Verilog語法撰寫完成，利用ModelSim模擬 FPGA結果與Matlab模擬結果比較，兩者之間的色差為0.9725。以上的色差值低於美國 國家標準與技術局所定義的色差在3以下人眼所可容忍色差之內。

7.2 未來展望

環場式膠囊內視鏡擁有錐狀鏡光學元件的關係而產生雜散光，而造成投光不平均 使得越靠近中心影像過曝，未來可以將環場式膠囊內視鏡的LED燈源照射於腸道壁

上，減少雜散光的產生。目前腸道影像接合時，所使用平均加權平滑法與最佳化縫隙 法為將影像模糊化，這樣會造成整體影像銳利度降低，造成影像品質只有小幅度的上 升。環場式膠囊內視鏡產生縫隙的問題在於投光不平均，所以可以由色彩空間的方式 將亮度拉為一致再進行接合影像減少縫隙產生。

本論文所提出演算法並非只侷限於內視鏡與環場式膠囊內視鏡，更適用於不同用 途之影像感測器，可以利用不同用途的影像感測器使用此演算法實現色彩校正，提升 此演算法價值並且由實驗中改善演算法的缺失。

影像感測器的暗雜訊較大，可以重新校正影像感測器，將暗雜訊影像降為最低。

FPGA實現色彩校正時因為雜訊的關係，將原本的雜訊放大，使得畫面不清楚，可以加 入數位影像處理的技術，將擷取到的影像先利用影像處理的技術將影像雜訊部分濾 除，再利用色彩校正演算法實現即時色彩校正。目前FPGA演算法利用三階層去實現即 時色彩校正，但是三階所能呈現的精準度並非最高，可以利用數位訊號處理將其運算 速度提升將演算法階數提升至八階，此階數可將色差降至1.324，提升影像色彩精確 度。現在已經完成FPGA即時色彩校正硬體實現，未來可以利用Design compiler 跟 IC compiler 將其演算法以IC形式呈現。

由於目前微創手術的盛行，內視鏡所利用的範圍將會越來的寬廣，目前的內視鏡 因為使用單一鏡頭，無法呈現出3D立體效果，造成在手術過程中因為景深的誤判，造 成傷害到其他的組織。傳統的3D攝影技術利用兩顆鏡頭去產生立體效果，但是內視鏡 會因為旋轉造成視平面改變，而無法產生全視角立體影像，故可以利用三顆鏡頭進行 產生3D立體影像，三顆鏡頭擁有著全視場的優勢，可以隨著內視鏡的旋轉改變視角產 生3D立體效果。

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個人著作

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專利：

[1] 歐陽盟，鄭偉德，賴建成，湯禹舜，「利用光纖成像之膠囊內視鏡」，專利申請中，

中華民國、日本、美國與大陸，民國99年。

[2] 歐陽盟，鄭偉德，賴建成，龔益群，陶冠亨，「全景式膠囊影像之裝置與方法」，專

利申請中，中華民國、日本、美國與大陸，民國100年。

[3] 歐陽盟，鄭偉德，賴建成，龔益群，陶冠亨，「3D全視場內視鏡系統」，專利申請

中，中華民國、日本、美國與大陸，民國100年。

競賽：

[1] 歐陽盟，鄭偉德，賴建成，龔益群，陶冠亨， 「3D全視場攝影之膠囊內視鏡系統」，

龍騰微笑競賽佳作，民國100年。