中文摘要

本研究中，建構出一套以一般光源對微小物件量測之非接觸式光學三次元量測系統。系統以CCD攝影機為取像裝置，搭配一可變倍率鏡頭，並設置一步進馬達來旋轉工件。藉由旋轉工件來減少光學取像之量測死角，以增進系統對非對稱複雜形狀之量測適用性。
在研究中，利用對焦尋形法來求得工件之三維輪廓資訊。此方法是應用Sum-Modified-Laplacian ( SML )運算子，藉由工件影像在對焦時清晰與失焦時模糊之差異，計算出工件輪廓之深度變化資訊。在SML運算處理前，先使用高斯平滑化濾波之影像處理技術，去除影像中不必要之背景雜訊，以提高SML運算子計算工件深度之精確性。在計算出各角度的XYZ三軸座標後，以齊性轉換矩陣做工件的三維座標旋轉轉換，求得工件之實際三維立體座標資訊，再加以重建工件輪廓及量測尺寸。
最後，以本研究建構出之量測系統對三種工件，進行實際取像量測，量測結果顯示此一系統之量測精度與接觸式量測系統之量測精度極為相近；且對於凹槽及凸起物等易造成光學取像死角之特徵形狀，能有效地取像量測，故本研究建構之量測系統可運用於實際量測上。

關鍵字：對焦尋形法，一般光源量測，齊性轉換矩陣。

Abstract

In this study, a novel 3D measurement system is developed. In this system, a CCD camera and zoom lens is used to grab object images and a stepping motor is used to rotate the object such that object image can be taken from several different directions. With the rotating device, it is able to reduce the optical limitations when reconstruct the 3D image of an asymmetric object or object with complicated shape.
In this system, the technology of Shape-from-Focus is adopted to estimate the 3D geometry of examined object. Gaussian smooth filter is adopted to remove the unnecessary background noise first. The Sum-Modified-Laplacian (SML) operator is then used as an index to determine whether the surface section of the examined object is in focus or not. After the coordinates of object surface from various viewing directions are determined, the actual coordinates of the object surface are determined by the homogeneous transformation matrix (HTM).
It is experimentally shown that the cone angle measured by the proposed system is quite close to that measured using a contact type 3-D coordinate measuring system. Object with complex features, such as grooves and protrusions, can also be observed with the proposed system.

Key word : Shape-from-Focus, homogeneous transformation matrix.

參考文獻

[1] 范光照, 章明, 姚宏宗, 許智欽, “逆向工程技術及應用,” 高立圖書有限公司, 1999.

[2] 廖克東, “應用機器視覺於低對比動態X-Ray影像強化及瑕疵偵測之研究( Low Contrast X-ray Image Enhancement and Defects Classification for Real-Time Dynamic System ),” 私立元智大學工業工程與管理學系碩士論文, 2001.

[3] 田亦凡, “高速超音波影像檢測系統( High Speed Ultrasonic Image Inspection System ),” 國立成功大學機械工程學系碩士論文, 2001.

[4] 劉寶信, “電子構裝三維尺寸之雷射量測( Laser Measure on The Three Dimensional Size of The IC Package ),” 國立成功大學工程科學系專班碩士論文, 2003.

[5] 張振龍, “360度立體快速量測系統與寬頻之應用( 360 Degrees Rapid Measuring System of 3-D Profilometry and Application in Wideband Network Collaboration ),” 國立台灣大學機械工程研究所碩士論文, 2000.

[6] 王彰群, “自製影像式量測儀之自動化研究( The Study of Automation in CCD Camera Measurement Device ),” 國立交通大學機械工程系碩士論文, 2001.

[7] 馮信榮,“二維影像於三維輪廓重建之研究,” 國立台灣大學機械工程研究所碩士論文, 2001.

[8] 周佳彥,”運用雙影像對應求取3D座標資訊-模擬退火法之應用” 朝陽科技大學工業工程與管理所碩士論文, 2003.

[9] Nayar, S. K. and Nakagawa, Y., “Shape from Focus : An Effective Approach for Rough Surfaces,” Proceedings of 1990 IEEE International Conference on Robotics and Automation, vol. 2, May 1990, pp.218-225, Cincinnati, USA.

[10] Ens, J. and Lawrence, P., “An Investigation of Methods for Determining Depth from Focus,” IEEE Transactions on Pattern Analysis and Machine Intelligence, Vol. 15, No. 2, Feb. 1993, pp.97-108.

[11] 陳時新, “實戰機器視覺,” 電子技術出版社, 1997.

[12] 吳成柯, 戴善榮, 程湘君, 雲立實, “數位影像處理,” 儒林圖書有限公司, 2001.

[13] 呂學仁, “利用數位影像進行硬碟片表面刮痕檢測可行性之研究( Feasibility Study Scratch Testing on Hard-Disk Surface Using Digital　Image Analysis ),” 國立清華大學動力機械工程學系碩士論文, 2001.

[14] Noguchi, M. and Nayar, S.K., “Microscopic Shape from Focus Using Active Illumination,” Proceedings of the 12th IAPR International Conference on Pattern Recognition, Vol. 1, Oct. 1994, pp.147-152, Jerusalem, Israel.

[15] Jähne, B. and Geißler, P., “Depth from Focus with One Image,” Proceedings CVPR '94., IEEE Computer Society Conference on Computer Vision and Pattern Recognition, June 1994, pp.713-717, Seattle, USA.
[16] Subbarao, M. and Choi, T., “Accurate Recovery of Three-Dimensional Shape from Image Focus,” IEEE Transactions on Pattern Analysis and Machine Intelligence, Vol. 17, No. 3, 1995, pp.266-274.

[17] Ishii, A., “3-D Shape Measurement Using a Focused-Section Method,” Proceedings of 15th International Conference on Pattern Recognition, Vol. 4, Sep. 2000, pp.828-832, Barcelona, Spain.

[18] 易明, “現代幾何光學,” 凡異出版社, 1992.

[19] Jia Li†, James Ze Wang‡, Robert M. Gray§, Gio Wiederhold, “Multiresolution Object-of-Interest Detection for Images with Low Depth of Field,” International Conference on Image Analysis and Processing, Sep. 1999, pp.32-37, Venice, Italy.

[20] Alexander H. Slocum, “Precision Machine Design,” Prentice-Hall International, Inc., 1992.

[21] 莊峻超, “逆向工程Imageware功能剖析,” 全華科技圖書股份有限公司, 2003.

[22] 林瑞璋, 王萬強, 陳文賢, “逆向工程軟體Surfacer使用手冊,” 全華科技圖書股份有限公司, 2002.

[23]尤春風, 陳宗伯, 陳柏瑞, 林益楓, 趙甦農, 林威延, “CATIA V5 使用手冊 曲面造型篇,” 知城數位科技有限公司, 2002.