著者

大坊 真洋 田山 典男 長谷川 辰雄 南幅 留男

出版者

The Society of Instrument and Control Engineers

雑誌

計測自動制御学会論文集 (ISSN:04534654)

巻号頁・発行日

vol.34, no.12, pp.1937-1944, 1998-12-31 (Released:2009-03-27)

参考文献数

25

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This paper describes a new approach to the X-ray computed tomography in order to find defects of the products in manufacturing industry. Our approach which is Fast Model Reconstruction Computed Tomography (FMR-CT), involves two key ideas: 1) for forward problem, integration two dimensional sinc functions along the X-ray on the sampled two-dimentional planee model and 2) for inverse problem, solving the liner inverse problem using a truncated singular value decomposition (SVD) method.Our algorithm is favorable fast computation capability because image vector can be obtained simple formula such as pseudo-inverse matrix (constant) multiplied by projection data vector, and is also compatible with multiprocessor implementations. The combination of sampling theorem and the SVD allows smooth reconstruction image with even smaller numbers of projections, because each techniques contribute interpolation and least-squares optimization, respectively.We demonstrate the cross section image which is reconstructed real projection data sets acquired by using the micro-focused X-ray TV. Further, we discuss practical determination of truncation rank with the visualization of decomposed v-singular vector and the distribution of singular values.

著者

長谷川 辰雄 土井 章男 松田 浩一

出版者

一般社団法人情報処理学会

雑誌

情報処理学会研究報告グラフィクスとCAD(CG) (ISSN:09196072)

巻号頁・発行日

vol.2003, no.15, pp.13-18, 2003-02-14

参考文献数

2

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本論文は,格子模様の網タイツや網目状のフィルムシートなどで物体を覆い,それを一般的なデジタルカメラで撮影し,ステレオ画像計測で3Dモデルを簡易的に構築するシステムを提案した.一般向けデジタルカメラは低価格で高解像度という特徴があるため,取り扱いが容易で画像処理精度を向上させることが可能である.格子模様の交差点をステレオ画像計測のマッチング点とし,2値化及び細線化によって交差点を抽出した.このとき,交差の角度が大きい箇所では,細線化によって歪みが生じるため,本論文では,それを修正するアルゴリズムを提案した.これらの処理によって,正確に抽出した交差点を元に,自動的に四角形ポリゴンの3Dモデルの構築が可能となり,また,ハードウェア構成が,デジタルカメラ,三脚,及びPCで構築できるため,システムの構築費が低価格で実現できた.The 3D object was covered with film sheet of grid, or the grid net, and it took pictures of that with the general digital still camera, and the system that the model 3D was built easily with stereophonic image measurement was developed. The digital still camera for the general purpose is high resolution in the low price. And that handling was easy, and it could improve image management precision. The crossing point of the grid pattern was the matching point of the stereophonic image measurement, and the crossing point was extracted by binarization and thinning. At this time, the distortion occurs by thinning in the point that angle big. This research developed the algorithm which corrected the distortion. This research built the model 3D of the quadrangle polygon automatically by the crossing extracted precisely. And, the construction cost of the system was a low price because hardware configuration could be built with the digital still camera and the tripod and the PC.