本研究提出一套在三維空間中的工件缺陷檢測系統，藉由結合電腦圖學和影像處理技術，進行工件的缺陷檢測，以虛擬空間中的工件模型資訊做為理想樣本，同時取得實際空間中的工件影像，經由影像處理萃取影像特徵和比對，獲得相關參數資訊後，進而評估工件是否符合設計標準。
本研究將自行設計一運動機構平台，平台上裝設一台攝影機，藉由平台的機構運動，使得攝影機可以相對於進行檢測的工件作一半球面的運動，並可拍攝工件相對於攝影機的任一視角之影像；擷取工件的影像後，將其輸入至系統，藉由OpenGL的開源程式函式庫，可將由工件的CAD模型轉換而來的.OBJ檔繪製於Microsoft Visual Studio的Windows Form視窗上，並模擬於虛擬空間中攝影機拍攝虛擬工件的視角影像，藉由同步實際和虛擬的工件影像後，以背景消去法將工件影像分割出來，之後以影像處理等技術將兩者影像進行比對，以檢測工件是否存在缺陷。由目前的實驗結果可知，本研究目前可偵測之最小缺陷尺寸為3 mm。

An inspection system for defects detection of three-dimensional workpieces is proposed. This work proposes an idea of implementation of defects detection by combining computer graphics and digital image processing. The virtual CAD model of the workpiece is taken as the ideal sample. Meanwhile, the image of the real workpiece is captured by the camera. The proposed system extracts the features from both the real and virtual images and compares them by image processing. The acquired information by image processing is evaluated to examine if the workpiece is acceptable.
A moving platform mechanism, on which a camera is set, will be built up in the system. The camera is enabled to move along a surface of hemisphere through the movement of the platform. Thus it is able to acquire the images of the workpiece from every viewpoint. The acquired image is then input to the system. The CAD model of the workpiece which is converted from the .OBJ file is drawn on the Windows Form of the Microsoft Visual Studio. In this way, the images rendered from different viewpoints can be simulated in the virtual environment. By synchronizing the real and virtual images, the images of the workpiece, which is segmented from background subtraction, can be inspected with image processing. Both the real and virtual images will be compared to check if any defect exists. So far, the minimal defect size which could be detected by the proposed system is 3 mm.

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