发明授权
- 专利标题: Estimation of local defocus distance and geometric distortion based on scanned image features
- 专利标题(中): 基于扫描图像特征估计局部散焦距离和几何失真
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申请号: US09750540申请日: 2000-12-28
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公开(公告)号: US06763141B2公开(公告)日: 2004-07-13
- 发明人: Beilei Xu , Robert P. Loce
- 申请人: Beilei Xu , Robert P. Loce
- 主分类号: G06K940
- IPC分类号: G06K940
摘要:
A method of estimating local defocus distance from a conventionally scanned image is provided. More particularly, the method of estimating defocus distance in a scanned image of a non-planar original object, such as an open book, includes scanning at least a portion of the book in order to produce scanned image data. An image feature obtainable from the scanned image data and a quantitative metric corresponding to the image feature are selected. Image feature data is extracted from the scanned image data and compared to a predetermined calibration relationship between the selected image feature and defocus distance in order to calculate a plurality of defocus distances, which are organized into a defocus distance map. The defocus distance map may be used in the subsequent correction of geometric distortions, blurring defects, and illumination variations adjacent the binding of an open book.