Method and device for counting a number of moving objects that cross at least one predefined curve in a scene

A device for counting a number of moving objects that cross at least one predefined curve in a scene, comprising:

• a detector configured to make detections of positions of one or more moving objects in the scene using data collected by a sensor device,
• a tracker configured to track the one or more moving objects in the scene over time based on the detections made by the detector to produce one or more corresponding tracks,
• a calculating unit configured to, for each moving object, calculate a success probability pi that the moving object succeeded to cross the at least one predefined curve in the scene, and a failure probability 1−pi that the moving object failed to cross the at least one predefined curve in the scene, the calculating unit being configured to calculate an expected value of a number of moving objects that crossed the at least one predefined curve,
• wherein the tracker is configured to describe each track by a time dependent probability density function,
• wherein the calculating unit is configured to calculate the success probability of a moving object by using the time dependent probability density function describing the track of the moving object, and to calculate a a variance of a number of moving objects that crossed the at least one predefined curve,
• wherein the expected value is calculated by summing success probabilities pi calculated with respect to the one or more moving objects, and the variance is calculated by summing products pi(1−pi) of success and failure probabilities calculated with respect to the one or more moving objects.

A non-transitory computer-readable medium comprising computer-code instructions adapted to carry out a method when executed by a device having processing capability, the method for counting a number of moving objects that cross at least one predefined curve in a scene, comprising:

• making detections of positions of one or more moving objects in the scene by using data collected by a sensor device,
• tracking the one or more moving objects in the scene over time based on the detections to produce one or more corresponding tracks,
• calculating, for each moving object, a success probability pi that the moving object succeeded to cross the at least one predefined curve in the scene, and a failure probability 1−pi that the moving object failed to cross the at least one predefined curve in the scene,
• calculating an expected value of a number of moving objects that crossed the at least one predefined curve, and
• calculating a variance of the number of moving objects that crossed the at least one predefined curve,
• wherein each track is described by a time dependent probability density function,
• wherein the success probability of a moving object is calculated by using the time dependent probability density function describing the track of the moving object, and
• wherein the expected value is calculated by summing success probabilities pi calculated with respect to the one or more moving objects, and the variance is calculated by summing products pi(1−pi) of success and failure probabilities calculated with respect to the one or more moving objects.