Apparatus and method for analyzing trajectory

Patent metadata

Field	Value
Publication number	US-9477887-B2
Application number	US-201514675878-A
Country	US
Kind code	B2
Filing date	Apr 1, 2015
Priority date	Apr 7, 2014
Publication date	Oct 25, 2016
Grant date	Oct 25, 2016

Abstract

A trajectory analyzing apparatus includes a matching unit that calculates the correlation between a forward trajectory obtained by tracking a moving object over pictures along the forward direction of the time axis and a backward trajectory obtained by tracking a moving object over the pictures along the backward direction of the time axis and a result output unit that outputs trajectory information indicating at least one of the forward trajectory, the backward trajectory, and an integrated trajectory obtained by integrating the forward trajectory and backward trajectory and indicating the degree of reliability of the at least one trajectory based on the calculated correlation.

First claim

What is claimed is:

1. A trajectory analyzing apparatus comprising:
a matching unit that calculates a correlation between a forward trajectory obtained by tracking a moving object over pictures, between a start picture and an end picture, along a forward direction of a time axis and a backward trajectory obtained by tracking a moving object over the pictures along a backward direction of the time axis; and
a result output unit that outputs trajectory information indicating at least one of the forward trajectory, the backward trajectory and an integrated trajectory obtained by integrating the forward trajectory and backward trajectory, and indicating a degree of reliability of the at least one trajectory based on the calculated correlation.

2. The trajectory analyzing apparatus according to claim 1 , further comprising a distance calculation unit that calculates a distance between the forward trajectory and backward trajectory at each time on the time axis, wherein
the correlation is higher when the calculated distance is shorter.

3. The trajectory analyzing apparatus according to claim 2 , further comprising:
a picture receiving unit that receives the pictures;
a start position setting unit that sets a forward start point on the start picture and a backward start point on the end picture, the forward start point being a start position of the forward trajectory, the backward start point being a start position of the backward trajectory;
a tracking unit that tracks a moving object located in the forward start point to generate the forward trajectory and tracks a moving object located in the backward start point to generate the backward trajectory; and
a trajectory integration unit that integrates the forward trajectory and backward trajectory to generate the integrated trajectory.

4. The trajectory analyzing apparatus according to claim 1 , further comprising a trajectory integration unit that integrates the forward trajectory and backward trajectory to generate the integrated trajectory,
wherein if at least one of the forward trajectory and backward trajectory comprises a plurality of trajectories, the matching unit determines a pair of the forward trajectory and backward trajectory which are more likely to have been generated with respect to the same moving object, on the basis of the correlation, and
wherein the trajectory integration unit integrates the determined pair of forward trajectory and backward trajectory to generate the integrated trajectory.

5. The trajectory analyzing apparatus according to claim 1 , further comprising a distance calculation unit that calculates a distance between the forward trajectory and backward trajectory at each time on the time axis,
wherein if at least one of the forward trajectory and backward trajectory comprises a plurality of trajectories, the matching unit determines, as a first pair, a pair of the forward trajectory and backward trajectory whose sum of the distances at the respective times on the time axis is equal to or smaller than a first threshold,
wherein the matching unit determines, as a second pair having a lower correlation than the first pair, a pair of the forward trajectory and backward trajectory which is obtained from other than the first pair, wherein a time at which the distance of the forward trajectory and backward trajectory is equal to or shorter than a third threshold is continuous over a time period which is equal to or longer than a fourth threshold on the time axis,
wherein the matching unit determines, as a third pair having a higher correlation than the second pair, a pair obtained from the first and second pairs, by excluding a pair whose forward trajectory or backward trajectory are included in both the first pair and second pair, and
wherein the matching unit sets the correlation lower than the correlation of the second pair to a trajectory which is not included in any of the first to third pairs, and
wherein the result output unit outputs the trajectory information indicating a difference in the reliability between the plurality of trajectories based on the correlation.

6. The trajectory analyzing apparatus according to claim 5 , wherein the matching unit determines, as a fourth pair having a higher correlation than the correlation of the third pair, a pair obtained from the third pair, by excluding a pair including the forward trajectory or backward trajectory whose distance to the other same directional trajectory is equal to or shorter than a fifth threshold at a certain time on the time axis.

7. The trajectory analyzing apparatus according to claim 1 ,
wherein the result output unit generates an image indicating the at least one trajectory as the trajectory information, and
wherein, in the image, a difference in the reliability between the plurality of trajectories is shown in the form of a difference in display form between the trajectories.

8. The trajectory analyzing apparatus according to claim 7 ,
wherein the result output unit generates the difference in display form, in the image, including at least one of a thickness of a line, a size or a shape of a marker, and a color, luminance, flashing or not, or a display timing of a line or a marker.

9. The trajectory analyzing apparatus according to claim 1 , further comprising a trajectory integration unit that integrates the forward trajectory and backward trajectory to generate the integrated trajectory, wherein
the trajectory integration unit generates the integrated trajectory by assigning higher weights to portions closer to a start point, of the forward trajectory and portions closer to a start point, of the backward trajectory.

10. The trajectory analyzing apparatus according to claim 1 , further comprising a trajectory integration unit that calculates tracking likelihoods of portions of the at least one trajectory on the basis of a distance between the forward trajectories at each time or a distance between the backward trajectories at each time, wherein
the result output unit outputs information about the calculated tracking likelihoods.

11. A method for analyzing a trajectory, comprising:
calculating a correlation between a forward trajectory obtained by tracking a moving object over pictures, between a start picture and an end picture, along a forward direction of a time axis and a backward trajectory obtained by tracking a moving object over the pictures along a backward direction of the time axis; and
outputting trajectory information indicating at least one of the forward trajectory, the backward trajectory and an integrated trajectory obtained by integrating the forward trajectory and backward trajectory, and indicating a degree of reliability of the at least one trajectory based on the calculated correlation.

12. A non-transitory computer-readable medium whose contents cause a computer to perform a process, the process comprising:
calculating a correlation between a forward trajectory obtained by tracking a moving object over pictures, between a start picture and an end picture, along a forward direction of a time axis and a backward trajectory obtained by tracking a moving object over the pictures along a backward direction of the time axis; and
outputting trajectory information indicating at least one of the forward trajectory, the backward trajectory, and an integrated trajectory obtained by integrating the forward trajectory and backward trajectory and indicating a degree of reliability of the at least one trajectory based on the calculated correlation.

13. The method according to claim 11 , further comprising:
calculating a distance between the forward trajectory and backward trajecto

Assignees

• Panasonic Corp

Inventors

• Kawaguchi Kyoko
• Sekii Taiki
• Tanabiki Masamoto

Classifications

• G06T7/246 Primary

  using feature-based methods, e.g. the tracking of corners or segments · CPC title

• G06T2207/30196

  Human being; Person · CPC title

• G06T2207/20076

  Probabilistic image processing · CPC title

• G06T7/2033

  Physics · mapped topic

• G06K9/4604

  Physics · mapped topic