Glare Aware Photography: 4D Ray Sampling for
Reducing Glare Effects of Camera Lenses
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Ramesh Raskar, Amit
Agrawal, Cyrus Wilson and Ashok Veeraraghavan ACM SIGGRAPH 2008 |
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Figure 1. Single shot
glare
reduction. We
extract
glare components from a single-exposure
photo in this high dynamic range scene.
Using a 4D analysis of glare inside the camera, we can emphasize or
reduce
glare. The photo in the middle shows a person standing against a sunlit
window.
We extract reflection glare generated inside lens and manipulate it to
synthesize the result shown on the left. On the right we show the
glare-reduced
component. Notice that the face is now visible with improved contrast.
Figure 2. Glare
reduction without loss of spatial resolution. We captured the photo
shown on the
left using a randomized pinhole array mask in the camera at f/4. A
projector on
the top-right corner in the scene (not shown) causes glare. By dividing
the
captured photo with a calibration photo, the mask effects are removed.
Note,
however, that the mask makes glare appear as high frequency 2D noise. A
glare
outlier stencil is obtained by comparing the ratio image with its
median
filtered output. The glare is reduced by interpolating the pixels in
outlier
stencil from neighboring pixels. All processing is done in 2D image
domain.
Figure 3. Our approach is single-shot and does not require high dynamic range image capture. Thus, photographers can use our camera as a regular handheld camera. Here we show four outdoor examples on glare reduction, where a single photo was captured.
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Summary First
'single-shot' approach to classify and reduce glare. We show that glare
manifests as an outlier in 4D ray space and use a statistical approach
to remove
it by 4D sampling without reconstructing a 4D-lightfield. Abstract |
Paper (Preprint) Low
res
pdf (4MB) High
res
pdf (27 MB)
Light Field Datasets for Glare Light Field Datasets for
Refocusing
SIGGRAPH 2006 Coded exposure for motion deblurring SIGGRAPH 2005 Combining flash/no-flash images using gradient domain algorithms for removing photography artifacts CVPR 2007
Simultaneous motion
deblurring and super-resolution
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Copyright 2008 by Mitsubishi Electric Research Labs (MERL),
Patents pending
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