近年來電子背向散射繞射技術(EBSD)經常運用於高變形量金屬材料、奈米材料上的分析，EBSD的空間解析度受限於掃描式電子顯微鏡(SEM)的電子束參數、電子束與試片交互作用體積、背向散射係數、原子序及試片厚度等影響。為了提升其空間解析度方法之一為降低電子束之加速電壓，然而降低電子束之加速電壓時，造成電子束與試片交互作用體積會縮小。因此，背向散射電子的數量與強度皆降低，而造成信噪比降低，致使菊池線圖之影像品質降低，導致能被軟體鑑定的菊池線數量減少，不利於後續分析。
本論文研究重點為如何在低信噪比下提升菊池線圖影像品質，論文內容主要分為三個部分，首先以影像處理方法，經由調整菊池圖之對比、清晰度以及雜訊等三種影響影像品質方法，藉此評估其影響，其次菊池圖背景扣除，有助於提升菊池線圖影像品質，因此提出三種菊池圖背景生成技術，最後評估菊池圖背景扣除後之最終菊池圖的品質，及優化CCD參數設定(曝光時間(exposure time)以及增益(gain))之最佳數值。
本論文利用三種菊池圖背景生成技術，均值法背景、傅立葉背景以及3D擬合背景，結合多種影像處理技術對原始菊池圖進行處理，將兩者進行扣除後，以三種客觀影像品質評估法為扣除背景後之菊池圖進行品質評分，比較均值法背景、傅立葉背景、3D擬合背景之間的差異以及三種菊池圖背景扣除後生成之菊池圖品質，歸納出優化菊池圖品質之最佳方法，並測試該方法於高加速電壓與低加速電壓下之應用。
研究結果顯示，當利用歸一化對15kV、5kV加速電壓下之原始菊池圖進行處理，並採用均值法、傅立葉以及3D擬合背景生成技術，歸一化菊池圖進行三種背景扣除後，15kV時IQ值分別為12993、10677、18652，Tenengrad variance值為5.14x106、2.92x107、7.33x107，SSEQ值為35.62、35.02、34.69；5kV時IQ值分別為4921、13699、24062，Tenengrad variance值為2.49x106、4.90x106、3.41x107，SSEQ值為18.54、19.68、18.92。不論是高加速電壓或低加速電壓的情況下，使用3D擬合菊池背景扣除技術所得之菊池圖品質皆優於均值法與傅立葉背景扣除技術。若在低加速電壓(5kV)的情況下使用3D擬合菊池圖背景扣除技術，CCD參數曝光時間以及增益值分別為500毫秒與5%，此參數下所生成之最終菊池圖品質最佳，IQ值為13211、Tenengrad variance值為3.41107、SSEQ值為18.92。

The quality of Kikuchi pattern is strongly influenced by accelerating voltage of electron beam. To improve the quality of Kikuchi pattern with low signal-to-noise ratio, image processing and background subtraction were applied. In this study, three background generation methods were used, including pattern averaging background, Fourier transformation background, and 3D fitting background. Among them, 3D fitting background is a novel method proposed. After background subtraction, the IQ (image quality) value of Kikuchi pattern by 3D fitting background subtraction is 24062, Tenengrad variance is 3.41107, and SSEQ is 18.92. The quality of Kikuchi pattern processed by 3D fitting background is better than that processed by Fourier transformation background and pattern averaging background subtraction at 5kV. For the case of 5kV, the best parameter setting for gain and exposure time are 5% and 500ms, respectively.

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