使用雙向性濾波器實現彩色影像增強及削減視訊雜訊

當影像和視訊經由通道傳輸和天線的感應器接收時通常都很容易受到雜訊的干擾，而由於這些干擾往往都會降低這些多媒體資料的品質而使得人眼感到不舒服，因此我們提出了一些削減雜訊的演算法來降低雜訊對於影像和視訊的影響。然而，許多研究顯示出，由於影像和視訊受到雜訊和模糊的侷限，因此有效削減雜訊的方法現今仍然是一大挑戰。現今有許多提出的演算法當中，雖然再削減雜訊功能上有傑出的結果，然後卻無法避免去產生人為的產物例如造成影像的模糊，這些都是由於雜訊和影像中的細節部分都屬於高頻的成分，要分辨他們就更加的困難。 1998年Tomasi和Manduchi提出了一種雙向性濾波器的概念，這個濾波器結合了區域濾波器以及值域濾波器分別來計算像素之間的幾何距離和像素亮度之間的相似度，以此可以削除影像的雜訊同時保留了影像中的細節。傳統上，雙向性濾波器只有針對灰階影像削除雜訊，在這篇論文當中，我們將此概念延伸到彩色影像，理論上，因為考慮到顏色的失真，所以我們可以得到比較好的結果，在後面的章節，我們會展示實驗的結果，由實驗的結果可以說明我們所提出的演算法可以在去除雜訊同時仍然保留影像的邊緣。雙向性濾波器被使用需用影像處理的應用上，除了削除影像雜訊以外，也可以用在處理影像的對比還有削減視訊雜訊。我們也會用2D的遮罩和3D的遮罩雙向性濾波器應用在削減視訊雜訊，當然，使用3D遮罩的雙向性濾波器有較好的結果並且不會產生鬼影。

關鍵字

雙向性濾波器；削減雜訊；增強對比

並列摘要

Images and videos are usually corrupted by noise when they are transmitted through communication networks and received from the sensors of antenna. Since the interference reduces quality of the multimedia, we consider the algorithm for noise reduction and design it to decrease the influence of noise. However, the researches for image denoising method are still a hard challenge because it is difficult to distinguish between edge texture and noise component since both of them belong to high frequency component. Therefore, many proposed algorithms which have an outstanding performance in the noise reduction but it is easy fail in avoiding artifact. Bilateral filter was proposed by C. Tomasi and R. Manduchi in 1998. The filter combines domain filter and range filter which measure geometric closeness and photometric similarity between pixels respectively to remove out noise for edge preserving in the spatial domain. Conventionally, bilateral filter is applied to denoise for grayscale image. This thesis extends the concept to color image for noise reduction. Theoretically, it has a better performance because it considered color distortion. The experiment shows the performance which successfully indicates our algorithm in noise reduction and preserving edge simultaneously. Bilateral filter is applied to many applications for image processing. In addition to image noise reduction, it is also applied to contrast management of high dynamic image and video noise reduction. We implement the filter based on 2D mask and 3D mask to video noise reduction and compare their outcome. Typically, the volumetric bilateral has better performance and doesn’t produce artifact.

並列關鍵字

Bilateral filter ； noise reduction ； contrast management

參考文獻

[25] Jiunn-Lin Wu, "An Automatic Enhancement Method for High Contrast Images via Bilateral Filtering", Journal of Science and Engineering Technology, Vol. 3, No. 3, pp. 81-87, 2007.

[1] C. Tomasi and R. Manduchi, “Bilateral filtering for gray and color images,” In Proc. of ICCV, pages 839-846, USA, 1998.

[3] F. Durrand and J. Dorsey, “Fast bilateral filtering for the display of high dynamic range images,” In Proc. of SIGGRAPH'02, pages 844.847, 2002.

[4] E. Eisemann, F. Durand, “Flash photography enhancement via intrinsic relighting.” ACM Trans. on Graphics23 (2004) Proc. of SIGGRAPH conference.

[5] Petschnigg, G., Agrawala, M., Hoppe, H., Szeliski, R., Cohen, M., Toyama, K, “Digital photography with flash and no-flash image pairs,“ ACM Trans. on Graphics23 (2004) Proc. of SIGGRAPH conference.

國際替代計量

使用雙向性濾波器實現彩色影像增強及削減視訊雜訊

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