System and method for registration of cubic fisheye hemispherical images

• US 20080284797A1
• Filed: 07/10/2008
• Published: 11/20/2008
• Est. Priority Date: 12/07/2000
• Status: Active Grant

• Current Assignee: iLOOKabout, Inc.
• Original Assignee: iLOOKabout, Inc.
• Inventors: Hack, Jeff
• Granted Patent: US 7,865,013 B2
• Time in Patent Office: Days
• US Class Current: 345/629
• CPC Class Codes: G06T 3/12 Panospheric to cylindrical image transformations

Abstract

Systems and methods for registering hemispheric images obtained using a fisheye lens for panoramic viewing, relating to spatial alignment and colour balancing of complement half-side images derived from the hemispheric images. The systems and methods for spatial alignment determine the displacement of the digitized recorded images using a single translation and rotation model of distortion, which further evaluates the centre of projection, and the extent of translation and rotation. The system and method for colour balancing iteratively increase (or decrease) the values of pixels near the edge (discontinuity) between the two half-sides of an image, each time taking into consideration the average difference of pixel colour across a smaller strip of the edge near the pixel. This invention removes the colour differential but does not remove any detail underlying the features of the image.

Claims

1. A computer-assisted method for aligning two digitized overlapping hemispheric images of an environment obtained with a fisheye lens comprising the steps of:

(a) receiving the location of three spatial points as recorded in the overlapping region of each hemispheric image;

(b) determining the translation and rotation of one hemispheric image relative to its ideal position from the locations of the three spatial points in the two images based on a displacement model; and

(c) obtaining the centre of projection in each image.

2. A system for aligning two digitized overlapping hemispheric images of an environment obtained with a fisheye lens comprising:

(a) a unit for receiving the location of three spatial points as recorded in the overlapping region of each hemispheric image;

(b) a unit for determining the translation and rotation of one hemispheric image relative to its ideal position from the locations of the three spatial points in the two images based on a displacement model; and

(c) a unit for obtaining the centre of projection in each image.

3. A method for balancing the color difference of two pixelated images joined together at an edge, comprising iteratively increasing (or decreasing) the values of pixels near the edge, each time taking into consideration the average difference of pixel colour across a smaller strip of the edge near the pixel.