Calculating time to go and size of an object based on scale correlation between images from an electro optical sensor

US8774457B2 · kind B2 · utility

Assignee

• SAAB AB · SE

Inventor

• Jimmy Jonsson · Säter, SE

Key dates

• Filing date: Mar 18, 2009
• Grant date: Jul 8, 2014
• Expiry date: Jun 27, 2030

Classification

• Technology area (CPC G): Physics
• CPC primary: G06T2207/30261
• WIPO field: Control
• WIPO sector: Instruments

Abstract

A method and a system for calculating a time to go value between a vehicle and an intruding object. A first image of the intruding object at a first point of time retrieved. A second image of the intruding object at a second point of time is retrieved. The first image and the second image are filtered so that the first image and the second image become independent of absolute signal energy and so that edges become enhanced. An X fractional pixel position and a Y fractional pixel position are set to zero. The X fractional pixel position denotes a horizontal displacement at sub pixel level and the Y fractional pixel position denotes a vertical displacement at sub pixel level. A scale factor is selected. The second image is scaled with the scale factor and resampled to the X fractional pixel position and the Y fractional pixel position, which results in a resampled scaled image. Correlation values, are calculated between the first image and the resampled scaled image for different horizontal displacements at pixel level and different vertical displacements at pixel level for the resampled scaled image. A maximum correlation value at a subpixel level is found based on the correlation v…