Identification Study Upon GeometricalTransformation of Image Point viaLocal Cross Correlation

碩士 === 國立成功大學 === 航空太空工程學系碩博士班 === 92 ===   An idealized model on re-constructing digital image between coarse and fine pixel image is proposed. The maximum local cross-correction coefficient method is employed to identify the associated point of an digital image with respect to another digital imag...

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Bibliographic Details
Main Authors: Chao-Wen Lo, 羅兆文
Other Authors: Y.N. Jeng
Format: Others
Language:zh-TW
Published: 2004
Online Access:http://ndltd.ncl.edu.tw/handle/46728265414089478480
Description
Summary:碩士 === 國立成功大學 === 航空太空工程學系碩博士班 === 92 ===   An idealized model on re-constructing digital image between coarse and fine pixel image is proposed. The maximum local cross-correction coefficient method is employed to identify the associated point of an digital image with respect to another digital image. The distance between two corresponding points is considered as the displacement between points. As comparing with the exact distance, the identification error can be defined. It is found that the following methods can improve the error on identification: shift the gray level value by an amount approximately equal to the maximum gray level of two images; construct the fine pixel image via the monotonic cubic spline interpolation to perform the fine grid identification; and employs a modified Shepard interpolation to perform selected interpolation which excludes all points with an extra- ordinary displacement. The linear conservative interpolation method is examined and is found to have a small effect of improving identification error because the proposed method of calculating the gray level gradient is improper. Sometimes, it is helpful to improve image visibility. The LoG filter is found to have potential to improve the estimation of edge image line in the fine grid calculation. Several motor plate images were employed to test the applicability of the proposed model.