Glare aware photography: 4D ray sampling for reducing glare effects of camera lenses

Glare arises due to multiple scattering of light inside the camera's body and lens optics and reduces image contrast. While previous approaches have analyzed glare in 2D image space, we show that glare is inherently a 4D ray-space phenomenon. By statistically analyzing the ray-space inside a camera, we can classify and remove glare artifacts. In ray-space, glare behaves as high frequency noise and can be reduced by outlier rejection. While such analysis can be performed by capturing the light field inside the camera, it results in the loss of spatial resolution. Unlike light field cameras, we do not need to reversibly encode the spatial structure of the ray-space, leading to simpler designs. We explore masks for uniform and non-uniform ray sampling and show a practical solution to analyze the 4D statistics without significantly compromising image resolution. Although diffuse scattering of the lens introduces 4D low-frequency glare, we can produce useful solutions in a variety of common scenarios. Our approach handles photography looking into the sun and photos taken without a hood, removes the effect of lens smudges and reduces loss of contrast due to camera body reflections. We show various applications in contrast enhancement and glare manipulation.

[1]  Vladimir Kolmogorov,et al.  An experimental comparison of min-cut/max- flow algorithms for energy minimization in vision , 2001, IEEE Transactions on Pattern Analysis and Machine Intelligence.

[2]  J A Seibert,et al.  Removal of image intensifier veiling glare by mathematical deconvolution techniques. , 1985, Medical physics.

[3]  Pat Hanrahan,et al.  Digital correction of lens aberrations in light field photography , 2006, International Optical Design Conference.

[4]  Sidney F. Ray,et al.  Applied Photographic Optics: Lenses and optical systems for photography, film, video, electronic and digital imaging , 2002 .

[5]  Alessandro Rizzi,et al.  Veiling glare: the dynamic range limit of HDR images , 2007, Electronic Imaging.

[6]  P. Hanrahan,et al.  Light Field Photography with a Hand-held Plenoptic Camera , 2005 .

[7]  John Hart,et al.  ACM Transactions on Graphics , 2004, SIGGRAPH 2004.

[8]  Marc Levoy,et al.  Veiling glare in high dynamic range imaging , 2007, ACM Trans. Graph..

[9]  Jan P. Allebach,et al.  Parametric point spread function modeling and reduction of stray light effects in digital still cameras , 2007, Electronic Imaging.

[10]  David Salesin,et al.  Spatio-angular resolution tradeoffs in integral photography , 2006, EGSR '06.

[11]  Marc Levoy,et al.  Light field microscopy , 2006, ACM Trans. Graph..

[12]  Edward H. Adelson,et al.  Single Lens Stereo with a Plenoptic Camera , 1992, IEEE Trans. Pattern Anal. Mach. Intell..

[13]  Marc Levoy,et al.  Reconstructing Occluded Surfaces Using Synthetic Apertures: Stereo, Focus and Robust Measures , 2006, 2006 IEEE Computer Society Conference on Computer Vision and Pattern Recognition (CVPR'06).

[14]  Jitendra Malik,et al.  Recovering high dynamic range radiance maps from photographs , 1997, SIGGRAPH '08.

[15]  Marc Levoy,et al.  Symmetric photography: exploiting data-sparseness in reflectance fields , 2006, EGSR '06.

[16]  Erik Reinhard,et al.  High Dynamic Range Imaging: Acquisition, Display, and Image-Based Lighting , 2010 .

[17]  H. Goszczynska,et al.  Estimation of the X-ray scatter and veiling glare rate in coronarographic densitometric measurements , 2000, Proceedings of the 22nd Annual International Conference of the IEEE Engineering in Medicine and Biology Society (Cat. No.00CH37143).

[18]  Ramesh Raskar,et al.  Dappled photography: mask enhanced cameras for heterodyned light fields and coded aperture refocusing , 2007, ACM Trans. Graph..

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

[20]  Takeshi Naemura,et al.  Glare generation based on wave optics , 2004, 12th Pacific Conference on Computer Graphics and Applications, 2004. PG 2004. Proceedings..

[21]  Donald P. Greenberg,et al.  Physically-based glare effects for digital images , 1995, SIGGRAPH.

[22]  Steve Marschner,et al.  Dual photography , 2005, ACM Trans. Graph..

[23]  Ramesh Raskar,et al.  Fast separation of direct and global components of a scene using high frequency illumination , 2006, SIGGRAPH 2006.

[24]  Richard Szeliski,et al.  The lumigraph , 1996, SIGGRAPH.

[25]  G. Skinner X-ray imaging with coded masks. , 1988, Scientific American.