A High-Performance Contrast Enhancement Algorithm Based on Regional Window Selection
| Autor: | Yu-Wen Tsai, 蔡育文 |
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| Rok vydání: | 2013 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 101 Contrast enhancement is used to improve the quality of low contrast images that are usually captured in poor environments. Considering contextual and variational characterization, a 2-D histogram based contrast enhancement algorithm was proposed. To balance contrast enhancement and brightness preservation, the window size of a 2-D histogram based contrast enhancement should be larger or smaller by considering the details of different parts in the image. Furthermore, its computation time is also an important issue for different real-time applications. In this paper, we propose a O(1) dynamic range 2-D histogram construction algorithm to effectively solve these problems. The proposed algorithm divides the image into various blocks and gives different neighbourhood size, which depends on the variation of intensity and the image details of each block. Compared to the prior work, the number of pixels are dynamically constructed in the 2-D histogram, while the integral histogram is achieved to be O(1) complexity. Experimental results show that the proposed algorithm generates high contrast images and preserves the local brightness in constant time. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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