加權分段色調映射之高動態影像顯示

Weighted Bi-Histogram Tone Mapping for High Dynamic Range Image Display

林彥廷(Yan-Ting Lin)

指導教授 ： 郭忠民

義守大學/電機資訊學院/資訊工程學系/碩士(2015年)

https://doi.org/10.6343/ISU.2015.00148

摘要

高動態範圍影像比起以往傳統低動態範圍影像能夠的到更多的資訊，而現有的顯示器通常大多是低動態範圍影像的顯示器。
為了將高動態範圍影像顯示在低動態範圍顯示器上，就有許多技術誕生，例如:色調映射、雙邊濾波…等等。利用這些方法將高動態範圍影像可以正常的顯示在低動態範圍顯示上面。
在本文中，我們提出了一種簡單的方法來做色調映射，先使用自動設定關鍵值β去進行色調映射，然後去計算映射後影像的亮度，利用標準影像的亮度來做權重值的分配。之後再提高降低關鍵值β映射兩張不同的影像，使用權重植來將兩張影像去進行融合。在權重值分配中，為了避免權重值在某些時候會發生過於趨近於零或一，所以我們限制了權重植最大值跟最小值。

關鍵字

高動態範圍影像 ； 色調再現 ； 色調映射 ； 雙邊濾波

並列摘要

Since high dynamic range image can record more detail image content than that of conventional low dynamic images, thus it receive much attention in recent years. However, most of monitors can only display low dynamic image. In order to solve this problem, researchers proposed tone mapping techniques. Tone mapping algorithms maps high dynamic range images to low dynamic range monitor effectively, and allows the monitors displaying the images with high dynamic range correctly.

In this thesis, we propose a mapping algorithm for displaying high dynamic range images. First, we set a key factor β for tone mapping, according to mapping lightness to adjust the combination weighting value. Then a high and low key factor set for extreme light and dark pixel value respectively. Finally, a scheme for determination of fusing weighting value is developed. Experimental results show satisfactory performance.

並列關鍵字

High Dynamic Range Imaging ； Tone mapping ； Bilateral Filtering

參考文獻

[5] 丁榮豐,“Based on Block Intensity Characteristic and Entropy Synthesized Differently Exposed Images for High Dynamic Range Images Generation” , 2009.

[1] Reinhard E., Stark M., Shirley P., and Ferwerda J.A. “Photographic tone reproduction for digital images” ACM SIGGRAPH, 2002.

[2] Fr’edo Durand, Julie Dorsey, “Fast Bilateral Filtering for the Display of High-Dynamic-Range Images”, ACM Trans. on Graphics, pp. 257–266, 2002.

[3] R.Fattal, D.Lischinski and M. Werman, “Gradient Domain. High Dynamic Range Compression”, ACM Trans. on Graphics, pp. 249–256, 2002.

[4] Michael Ashkhmin “A Tone Mapping Algorithm for High Contrast Images”, Eurographics Workshop on Rendering (2002), pp. 1–11, 2002.