Removing motion blur from a single image Sources
Removing motion blur from a single image
Sources of blur • Object motion
Sources of blur • Object motion • Translation of camera
Sources of blur • Object motion • Translation of camera • Rotation of camera
Sources of blur • Object motion • Translation of camera • Defocus • Rotation of camera • Internal camera distortions
Point Spread Function (PSF) Assume: • Point light source PSF =
Convolution model motivation • Assume: – No image plane rotation – No object motion during the exposure – No significant parallax (depth variation) • Violation of assumption: Camera motion is Pure Translation!!!
Convolution model motivation • Assume: – No image plane rotation – No object motion during the exposure – No significant parallax (depth variation) Camera motion is Pure Translation!!! • Experimental validation: 8 subjects handholding DSLR with 1 sec exposure Close-up of dots
Convolution Model • Notations – L: original image – K: the blur kernel (PSF) – N: sensor noise (white) – B: input blurred image Generation rule: B = K L + N +
How can the image be recovered? Goal: • Recover L s. t. : B =K L Assumptions: • Known kernel (PSF) • Constant kernel for the whole image • No noise Fourier Convolution Theorem!
De-blur using Convolution Theorem:
Example: PSF Blurred Image Recovered
Noisy case: Example: Deconvolution is unstable
1 D example: FT of original signal Original signal Reconstructed FT of the signal FT of convolved signals Convolved signals w/w noise Regularization is required
Regularizing by window Window size: 51 191
- Slides: 15