公开(公告)号：US10783662B2

公开(公告)日：2020-09-22

申请号：US16437513

申请日：2019-06-11

申请人： Axis AB

发明人： Mikael Nilsson

IPC分类号： G06T7/73 ,  G06T7/593 ,  H04N13/239 ,  H04N13/00

摘要： A method for estimating a sub-pixel position of an extreme point in an image uses a parametric function. The parametric function is fitted locally to a group of neighboring pixels in the image, and a spatial position of an extreme point of the parametric function is identified. If the extreme point of the parametric function is of a different type than the extreme point in the image, or the position of the extreme point of the parametric function is located outside an area defined by the pixel positions in the group of neighboring pixels, a pixel is removed from the group of neighboring pixels and the fitting of the parametric function is repeated. In the end, the sub-pixel position is estimated as the position of the extreme point of the parametric function. A level of uncertainty of the estimated sub-pixel position is estimated as the number of repetitions needed before arriving at the estimate of the sub-pixel position.

公开(公告)号：US20190378297A1

公开(公告)日：2019-12-12

申请号：US16437513

申请日：2019-06-11

申请人： Axis AB

发明人： Mikael Nilsson

IPC分类号： G06T7/73 ,  G06T7/593 ,  H04N13/239

摘要： A method for estimating a sub-pixel position of an extreme point in an image uses a parametric function. The parametric function is fitted locally to a group of neighboring pixels in the image, and a spatial position of an extreme point of the parametric function is identified. If the extreme point of the parametric function is of a different type than the extreme point in the image, or the position of the extreme point of the parametric function is located outside an area defined by the pixel positions in the group of neighboring pixels, a pixel is removed from the group of neighboring pixels and the fitting of the parametric function is repeated. In the end, the sub-pixel position is estimated as the position of the extreme point of the parametric function. A level of uncertainty of the estimated sub-pixel position is estimated as the number of repetitions needed before arriving at the estimate of the sub-pixel position.

公开(公告)号：US11640680B2

公开(公告)日：2023-05-02

申请号：US17111571

申请日：2020-12-04

申请人： Axis AB

发明人： Håkan Ardö ,  Mikael Nilsson ,  Karl Erik Åström ,  Martin Ahrnbom

IPC分类号： G06T7/80 ,  G06T7/73 ,  G06T7/70 ,  G01C3/02

摘要： An imaging system is described having at least three cameras and a processing unit. The at least three cameras have a common field of view and camera centres positioned along a line. The at least three cameras are configured to image a calibration object to generate a set of calibration object images, wherein the calibration object is located nearby the at least three cameras and in the common field of view. The at least three cameras are further configured to image a scene comprising a set of distant scene position points to generate a set of position point images. The processing unit is configured to generate a set of calibration parameters in dependence on the set of calibration object images and the set of position point images.