Glare Aware Photography: 4D Ray Sampling for
Reducing Glare Effects of Camera Lenses
|Ramesh Raskar, Amit
Agrawal, Cyrus Wilson and Ashok Veeraraghavan
ACM SIGGRAPH 2008
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
the top-right corner in the scene (not shown) causes glare. By dividing
captured photo with a calibration photo, the mask effects are removed.
however, that the mask makes glare appear as high frequency 2D noise. A
outlier stencil is obtained by comparing the ratio image with its
filtered output. The glare is reduced by interpolating the pixels in
stencil from neighboring pixels. All processing is done in 2D image
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.
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.
Light Field Datasets for Glare
SIGGRAPH 2006 Coded exposure for motion deblurring
Copyright 2008 by Mitsubishi Electric Research Labs (MERL),