高動態影像合成中新色彩對應之研究

color image enhancement by using adaptive transfer fucntion

徐道義(Tao-I Hsu)

《中華印刷科技年報》 2016 (2016/04) Pp. 133-138

摘要

HDR影像的亮度範圍涵蓋很廣，依據影像之亮度變化可將HDR影像大致分為低、中、高亮度景像，低亮度景像定義為影像中大部分的亮度的數值均非常小，幾乎看不見影像中的細節輪廓。中亮度景像定義為影像中明視度分佈較低亮度景像亮，可由眼睛直接察覺影像中的物件與細節。而高亮度景像定義為影像中大部分的亮度的數值均非常大，在視覺上，影像中的物件均因有很大的亮度，因此眼睛無法直接觀察到影像物件資訊。上述三種景像資訊無法直接被化簡。因此為了解決兩極端景像低、高亮度景像，本研究提出採用自動機制依據影像原始的特性，自動地增強低亮度影像，降低高亮度影像亮度值，期使影像細節資訊能顯著的顯現出，達影像增強之目的。

關鍵字

高動態顯像範圍 ； 雙向濾波器 ； 色調對應

並列摘要

One usual situation of most high-contrast images is the coexistence of dark shadows and bright light source in one scene. It is very difficult to present details in both dark and bright areas simultaneously on most display devices. In order to overcome this problem, a new method utilizing bilateral filter combined with adaptive tone-mapping method is proposed to improve image quality. Bilateral filter is first used to decompose image into two layers: large-scale layer and detail layer. Then, the large scale layer image is divided into three regions: bright, mid-tone, and dark region. Followed by an appropriate tone-mapping method is chosen to process each region according to its individual property. Only large-scale layer image is enhanced by using adaptive tone mapping; therefore, the details of the original image can be preserved. The experiment results demonstrate the success of proposed method. Furthermore, the proposed method can also avoid posterization produced by methods using histogram equalization.

並列關鍵字

High Dynamic Range ； Bilateral filters

參考文獻

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