Optimal Single Image Capture for Motion Deblurring


Amit Agrawal and Ramesh Raskar
CVPR 2009


Deblurring images of moving objects captured from a traditional camera is an ill-posed problem due to the loss of high spatial frequencies in the captured images. Recent techniques have attempted to engineer the motion point spread function (PSF) by either making it invertible using coded exposure, or invariant to motion by moving the camera in a specific fashion. We address the problem of optimal single image capture strategy for best deblurring performance. We formulate the problem of optimal capture as maximizing the signal to noise ratio (SNR) of the deconvolved image given a scene light level. As the exposure time increases, the sensor integrates more light, thereby increasing the SNR of the captured signal. However, for moving objects, larger exposure time also results in more blur and hence more deconvolution noise. We compare the following three single image capture strategies: (a) traditional camera, (b) coded exposure camera, and (c) motion invariant photography, as well as the best exposure time for capture by analyzing the rate of increase of deconvolution noise with exposure time. We analyze which strategy is optimal for known/unknown motion direction and speed and investigate how the performance degrades for other cases. We present real experimental results by simulating the above capture strategies using a high speed video camera.

Paper (Preprint)


Related Papers in Motion/Focus Deblurring

SIGGRAPH 2006      Coded exposure for motion deblurring
SIGGRAPH 2007      Coded aperture and a new theory of light field capture
SIGGRAPH 2009      Invertible Motion Blur in Video

CVPR 2007              Simultaneous motion deblurring and super-resolution
CVPR 2009              New codes for coded exposure deblurring to help in PSF Estimation

Figure 1. (Left) We consider object motion in terms of magnitude and direction. If both magnitude and direction are known, trivial capture strategy is to move the camera in that direction with that magnitude. Both coded exposure and MIP will also work well. If direction is unknown and magnitude is known, coded exposure should be used (left col). As magtnitude changes, the performace of coded exposure degrades gradually. If direction is known and magnitude is unknonw, MIP should be used  However, as the direction changes, MIP performace degrades sharply.

Back to my homepage