Removing motion blur from a single image

1
Removing motion blur from a single image
2
Sources of blur

• Object motion

3
Sources of blur

• Object motion
• Translation of camera

4
Sources of blur

• Object motion
• Translation of camera
• Rotation of camera

5
Sources of blur

• Object motion
• Translation of camera
• Rotation of camera

• Defocus
• Internal camera distortions

6
Point Spread Function (PSF)

• Assume
• Point light source

7
Convolution model motivation

• Assume
• No image plane rotation
• No object motion during the exposure
• No significant parallax (depth variation)

Camera motion is Pure Translation!!!

• Violation of assumption

8
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
9
Convolution Model

• Notations
• L original image
• K the blur kernel (PSF)
• N sensor noise (white)
• B input blurred image

?

10
How can the image be recovered?

• Assumptions
• Known kernel (PSF)
• Constant kernel for the whole image
• No noise

• Goal
• Recover L s.t.

B K ? L
11
De-blur using Convolution Theorem
Convolution Theorem
12
Example
PSF
Blurred Image
13
Noisy case
14
1D example
Regularization is required
15
Regularizing by window
Window size