Crofts, William Edward (2007) The generation of depth maps via depth-from-defocus. PhD thesis, University of Warwick.

Preview	PDF WRAP_THESIS_Crofts_2007.pdf - Submitted Version - Requires a PDF viewer. Download (4Mb) | Preview
	Other (Email acceptance of digitisation) FW Digitisation of your PhD thesis.msg Embargoed item. Restricted access to Repository staff only Download (4Mb)

Request Changes to record.

Abstract

The principle aim of this study was to use the concept of image defocus related to feature depth in order to develop a system capable of converting a 2-dimensional greyscale image into a 3-dimensional depth map. An advantage of this concept (known as depth-from-defocus or simply DfD) over techniques such as stereo imaging is that there is no so-called ‘correspondence problem’ where the corresponding location of a feature or landmark point must be identified in each of the stereo images.

The majority – and the most successful – of previous researchers in DfD have used some variation of a ‘two-image’ technique in order to separate the contribution of the original scene features from the defocus effect. The best of those have achieved results typically in the range of 1% to 2% error in the accuracy of depth estimation. This thesis presents a single-image method of generating a high-density, highaccuracy depth map via the evaluation of the edge profiles of a projected structured light pattern. A novel technique of moving the projected pattern during the image capture stage allows the development of a 4-dimensional look-up table. This technique offers a solution to one of the last remaining problems in DfD, that of spatial variance. It also uses a technique to remove the dependence of original scene reflectance. The final solution generates a depth map of up to 240,000 spatially invariant depth estimates per scene image, with an accuracy of within ± 0.5%, over a depth range of 10 cm. The depth map is generated in a processing time of approximately 14 seconds once the images are loaded.

Item Type:	Thesis (PhD)
Subjects:	T Technology > TR Photography
Library of Congress Subject Headings (LCSH):	Depth of field (Photography), Image processing -- Digital techniques, Images, Photographic
Official Date:	September 2007
Dates:	Date Event September 2007 Submitted
Institution:	University of Warwick
Theses Department:	School of Engineering
Thesis Type:	PhD
Publication Status:	Unpublished
Supervisor(s)/Advisor:	Staunton, R. C.
Extent:	xiii, 250 leaves
Language:	eng

Request changes or add full text files to a record

Repository staff actions (login required)

View Item