碩士 / 國立中央大學 / 土木工程研究所 / 96 / Since the ocean pollution usually causes severe damage to the environment and economy, it is the important issue for detecting the pollution rapidly. The satellite imagery could provide observations of wide areas; it can be used for detecting the anomaly which may be the pollution on the ocean. Generally, the anomaly is defined as the object with different characteristics of reflectance from the background. Base on this definition, the automatic algorithm could be developed to detect the anomaly.
In this study, a three-stage algorithm is proposed to detect the anomaly automatically: (1) Use RX (Reed & Xiaoli) algorithm to derive the RX image which represents the intensity of the anomaly. (2) Use EM (Expectation-Maximization) algorithm to classify the image into two probability distribution functions which represents the anomaly and background respectively. Then a threshold is determined to binarize the image to show up the anomaly. (3) In order to reduce the noise, the region growing algorithm is used to refine the anomaly image.
Various satellite images are used to test the proposed algorithm. The results show that the shape, area, and location of ocean anomaly could be observed clearly and accurately. Furthermore, the accuracy information could be estimated to evaluate the result.
| Identifer | oai:union.ndltd.org:TW/096NCU05015055 |
| Creators | Yi-Chung Ke, 柯弈仲 |
| Contributors | Chi-Farn Chen, 陳繼藩 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 102 |
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