Generating categorical depth maps using passive defocus sensing
US5793900A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 29, 1995 |
| Grant date | Aug 11, 1998 |
| Priority date | — |
| Expiry date | Dec 29, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T2207/20021
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method is disclosed for generating a categorical depth map of a scene using passive defocus sensing. In a preferred embodiment three synchronized CCD cameras focused at different distances detect three images of the same scene. An image processor partitions the images into an array of regions and calculates a sharpness value for each region. The sharpness value for a region is calculated by summing over all pixels (x,y) in the region the absolute difference in the intensity value of a pixel (x,y)( with pixel (x-k,y-l), where k and l are constants. The image processor then constructs a depth map of the scene by determining for each region the image with the greatest sharpness in that region. An application of the invention to a mobile robot control system is described in detail. Among other applications, the method may be used for collision avoidance, object detection, and speed measurement.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.