本研究針對單一感測元件之數位相機所拍攝的影像，可能產生假 色現象與拉鏈型效應的人工錯色情形，提出一種基於鄰近像素邊緣方 向資訊的色彩內插演算法。此方法包含兩個處理步驟，第一個步驟為 初始演算法的部分，使用鄰近像素的邊緣方向與方向修正機制，提升 估測未知像素內插方向的準確度。第二個步驟為優化演算法的部份，
本研究提出一種新的優化處理的方式，可以有效抑制人工錯色的情形 產生，並提升重建影像的視覺品質。
根據實驗模擬結果，本文所提出來的內插演算法，在客觀的層面 上，藉由峰值訊號雜訊比與 S-CIELab 兩個評估工具，都證實比其他 的演算法得到更好的效果。在主觀層面上，藉由實際人眼的視覺感受 進行重建影像品質的評估，也證明具有較佳的視覺品質。此外在計算 複雜度上，大幅降低部分疊代型演算法所需要的大量運算與計算時間。
為了獲得更好的重建影像，必須考慮到影像中邊緣或細節區域的 各種型態，針對不同的型態採取合適的內插估測方式，此外在對角方 向的邊緣未知像素還需要提出更適當的估測方式，以減少拉鏈型效應 的產生。未來工作將針對這些問題進行研究與實驗，找出更有效應付 各種細節型態與邊緣情形的內插估測方式，以獲得更完美的重建影像。
參考文獻
[1] B. E. Bayer, “Color imaging array,” U.S. Patent 3 971 065, Jul. 1976.
[2] H. S. Hou et al., “Cubic splines for image interpolation and digital filtering,” IEEE Trans. Acoust., Speech, Signal Process., Vol.
ASSP-26, No.3, pp. 508–517, June 1987.
[3] S.-C. Pei and I.-K. Tam, “Effective color interpolation in CCD color filter arrays using signal correlation,” IEEE Trans. Circuits Systems Video Technol., vol. 13, no. 6, pp. 503-513, Jun. 2003.
[4] J. E. Adams, “Interactions between color plane interpolation and other image processing functions in electronic photography,” Proc. SPIE 2416, pp. 144–151, 1995.
[5] J. F. Hamilton Jr. and J. E. Adams, “Adaptive color plane interpolation in single color electronic camera,” U. S. Patent 5 629 734, May 1997.
[6] B. K. Gunturk, Y. Altunbasak, and R. M. Mersereau, “Color plane interpolation using alternating projections,” IEEE Trans. Image Process., vol. 11, no. 9, pp. 997-1013, Sep. 2002.
[7] X. Li, “Demosaicing by successive approximation,” IEEE Trans.
Image Process., vol. 14, no. 3, pp. 370-379, March 2005.
[8] C.-Y. Su, “Highly effective iterative demosaicing using weighted-edge and color-difference interpolation,” IEEE Trans. Consumer Electronics, vol. 52, no. 2, pp. 639-645, May 2006.
[9] J. E. Adams Jr, “Design of practical color filter array interpolation algorithms for digital cameras,” Proc. SPIE, vol. 3028, pp. 117-125, Feb. 1997.
[10] W. Lu and Y.-P. Tan, “Color filter array demosaicing: New method and performance measures,” IEEE Trans. Image Process., vol. 12, no.
10, pp. 1194-1210, Oct. 2003.
[11] P.-S. Tsai, T. Acharya, A. K. Ray, “Adaptive fuzzy color interpolation,” Journal of Electronic Imaging, vol. 11, pp. 1-24, July 2002.
[12] L. Chang and Y.-P. Tan, “Effective use of spatial and spectral correlations for color filter array demosaicking,” IEEE Trans. on consumer electronics, vol. 50, no. 1, pp. 355-365, Feb. 2004.
[13] D. D. Muresan and T. W. Parks, “Demosaicing using optimal recovery,” IEEE Trans. Image Process., vol. 14, no. 2, pp. 267-278, Feb. 2005.
[14] L. Chen, K.-H. Yap, and Y. He, “Color filter array demosaicking using wavelet-based subband synthesis,” IEEE. Int. Conf. Image Process., 2005, vol. 2, pp. 1002-1005.
[15] D. Alleysson, S. Süsstrunk, and J. Hérault, “Linear demosaicing inspired by the human visual system,” IEEE Trans. Image Process., vol. 14, no. 4, pp. 439-449, April 2005.
[16] R. Kimmel, “Demosaicing: Image reconstruction from CCD samples,” IEEE Trans. Image Process., vol. 8, no.9, pp. 1221-1228, Sep. 1999.
[17] X. Li and M. Orchard, “New edge directed interpolation,” IEEE Trans. Image Process., vol. 10, no. 10, pp. 1521-1527, Oct. 2001.
[18] K. Hirakawa and T. W. Parks, “Adaptive homogeneity-directed demosaicing algorithm,” IEEE Trans. Image Process., vol. 14, no. 3, pp. 360-369, March 2005.
[19] L. Chang and Y.-P. Tan, “Hybrid color filter array demosaicking for effective artifact suppression,” Journal of Electronic Imaging, vol.
15(1), pp. 1-17, Jan.-Mar. 2006.
[20] W. Lee et al., “Cost-effective color filter array demosaicing using spatial correlation,” IEEE Trans. Consumer Electronics, vol. 52, no. 2, pp. 547-554, May 2006.
[21] C.-Y. Su, “Low-complexity hybrid demosaicing for color filter arrays,” Journal of Chinese Institute of Engineers, vol. 31, no. 1, pp.
173-179, 2008.
[22] T. W. Freeman, “Median Filter for Reconstructing Missing Color Samples,” U.S. Patent 4 724 395, 1988.
[23] Kodak test images and the demosaicing code of successive
approximation available at http://www.csee.wvu.edu/~xinl/demo/demosaic.html.
[24] S-CIELab Metric (2003). [Online]. Available at http://white.stanford.edu/~brian/scielab/scielab.html.