A focus measure for light field rendering

Light field rendering is a fundamental method for synthesizing free-viewpoint images from a set of multiviewpoint images. In the simplest case, the scene structure is approximated by a simple plane: a focal plane. This approximation leads to focus-like effects on synthetic images where the focused depth is determined by the focal plane. A serious problem is that the range of the focused depth is too small in most practical cases. In this paper, we propose a focus measure that is specialized for synthetic images by light field rendering. When a set of differently-focused images is generated at a given viewpoint, the proposed focus measure enables us to obtain a depth map and an all in-focus image. Our approach has some remarkable differences from other related techniques, such as depth-from-stereo and depth-from-focus methods. Experimental results show that the proposed method effectively enhances PSNR of the final synthetic images.

[1]  S. B. Kang,et al.  Survey of image-based representations and compression techniques , 2003, IEEE Trans. Circuits Syst. Video Technol..

[2]  Harry Shum,et al.  Plenoptic sampling , 2000, SIGGRAPH.

[3]  Takeshi Naemura,et al.  Depth of field in light field rendering , 2003, Proceedings 2003 International Conference on Image Processing (Cat. No.03CH37429).

[4]  Takeshi Naemura,et al.  Focus measurement on programmable graphics hardware for all in-focus rendering from light fields , 2004, IEEE Virtual Reality 2004.

[5]  Leonard McMillan,et al.  Dynamically reparameterized light fields , 2000, SIGGRAPH.

[6]  Takeo Kanade,et al.  When Is the Shape of a Scene Unique Given Its Light-Field: A Fundamental Theorem of 3D Vision? , 2003, IEEE Trans. Pattern Anal. Mach. Intell..

[7]  Takeshi Naemura,et al.  All in-Focus View Synthesis from Under-Sampled Light Fields , 2003, ICAT.

[8]  Marc Levoy,et al.  Light field rendering , 1996, SIGGRAPH.

[9]  Leonard McMillan,et al.  A new reconstruction filter for undersampled light fields , 2003 .

[10]  Shree K. Nayar,et al.  Shape from Focus , 1994, IEEE Trans. Pattern Anal. Mach. Intell..