Skip to Main content Skip to Navigation
Theses

Removing camera shake blur and unwanted occluders from photographs

Abstract : This thesis investigates the removal of spatially-variant blur from photographs degraded by camera shake, and the removal of large occluding objects from photographs of popular places. Spatially-variant blur caused by camera shake is modelled using a weighted set of camera poses, which induce homographies on the image. The blur in an image is parameterised by the set of weights, which fully describe the spatially-variant blur at all pixels. We demonstrate direct estimation of the blur weights from single and multiple images captured by conventional cameras, by adapting existing (spatially-invariant) deblurring algorithms. This permits a sharp image to be recovered from a blurry "shaken" image without any user interaction. To reduce the computational cost of our model, we introduce an approximation based on local-uniformity of the blur. By grouping pixels into local regions which share a single PSF, we can use fast 2D convolutions to perform the blur computation. For deblurring images with saturated pixels, we modify the forward model to include this non-linearity, and re-derive the Richardson-Lucy algorithm. To prevent ringing appearing in the output, we propose separate updates for pixels affected/not affected by saturation. In order to remove large occluders from photos, we automatically retrieve a set of exemplar images of the same scene from the Internet. We extract homographies between each of these images and the target image to provide pixel correspondences. Finally we combine pixels from several exemplars in a seamless manner to replace the occluded pixels, by solving an energy minimisation problem.
Complete list of metadatas

https://tel.archives-ouvertes.fr/tel-00719092
Contributor : Abes Star :  Contact
Submitted on : Thursday, July 19, 2012 - 9:27:20 AM
Last modification on : Thursday, October 29, 2020 - 3:01:54 PM
Long-term archiving on: : Saturday, October 20, 2012 - 2:30:12 AM

File

Whyte2012.pdf
Version validated by the jury (STAR)

Identifiers

  • HAL Id : tel-00719092, version 1

Collections

Citation

Oliver Whyte. Removing camera shake blur and unwanted occluders from photographs. General Mathematics [math.GM]. École normale supérieure de Cachan - ENS Cachan, 2012. English. ⟨NNT : 2012DENS0013⟩. ⟨tel-00719092⟩

Share

Metrics

Record views

618

Files downloads

623