The Generation of Depth Maps via Depth-from-Defocus

The principal 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 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 book presents a single-image method of generating a high-density, high-accuracy depth map via the evaluation of the edge profiles of a projected structured light pattern. 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 10cm.

Autorentext

Dr William Crofts is currently a Principal Teaching Fellow who is lecturing in engineering at the University of Warwick. He completed an MSc by Research in Medical Imaging (Coventry), before completing his PhD at the University of Warwick. He has also worked extensively in industry in his home town of Coventry in the UK.