Edge Detection Based SWIR Image Bad Pixel Detection and Correction
| Autor: | Wu, Yung-Fa, 吳泳發 |
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| Rok vydání: | 2011 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 100 In this thesis, we first use edge detection and fuzzy rules to find bad pixel map of a SWIR sensor. Then we employ two median filters sequentially to correct them. Moreover, we apply two-point correction method to correct non-uniformity among pixels of SWIR sensor. To enhance the tools for bad pixel correction, we have also proposed a new color edge detector based on vector order statistics. The proposed detector consists of two stages. In the first stage, we use fuzzy gradient to estimate the direction of the gradient for every processing pixel in the image and adjust the corresponding processing window according to this detected direction for reliable edge detection setup. The second stage computes the vector mean distance (VMD) based on vector order statistics. Hence, the proposed detector, which integrates vector order statistics and fuzzy gradient, can provide more robust response for edge detection. Furthermore, we also combine the edge detector to our proposed thresholding method, which can automatically determine an optimal threshold and be adaptive to different image contents without manual intervention. Thus, the excellent results by our proposed edge detection scheme demonstrate that it is very user friendly and confident. This edge detection scheme could also be promising for better detecting bad pixels of a SWIR image sensor. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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