Method and device for counting pedestrians based on identification of head top of human body

A device for counting pedestrians based on an identification of a head top of a human body, wherein the device comprises:

• a foreground acquiring unit configured to read a pedestrian depth image taken by a depth camera, and compare the pedestrian depth image and a pre-acquired environmental mean image to acquire a foreground image of the pedestrian depth image;
• a region detecting unit configured to divide the foreground image into a plurality of regions, detect whether or not there is a step in an edge pixel point of each of the plurality of regions, and detect whether or not a region curved surface formed in each region coincides with a curved surface of the head top of the human body;
• a head top determining unit configured to determine that a currently detected region is a region of the head top of the human body when there is a step in the edge pixel point of the currently detected region and when the region curved surface formed in the currently detected region coincides with the curved surface of the head top of the human body;
• and
• a pedestrian number outputting unit configured to count and output a number of pedestrians according to the region of the head top of the human body determined from the pedestrian depth image and the region of the head top of the human body determined from an adjacent pedestrian depth image;
• wherein the region detecting unit comprises:
• an arc setting unit configured to, for each region of the plurality of regions, take n pixel points at an edge of the respective region, take the n pixel points as an arc centre, and make arcs having a radius of r outside the respective region, respectively, to acquire n arcs, wherein a distance between two adjacent pixel points in the n pixel points is a preset fixed value;
• an arc identifying unit configured to, for each region of the plurality of regions, take k pixel points on each of the arcs to acquire, from the k pixel points, a number of the pixel points whose value is greater than a value of the arc centre of the arc, denote the number as a first number, identify the arc as a positive arc when the ratio between the first number and k is greater than a first preset ratio, otherwise identify the arc as a negative arc;
• and
• a step determining unit configured to, for each region of the plurality of regions, count the number of positive arcs in the n arcs at the edge of the respective region, and determine that there is a step in the edge pixel point of the respective region when the number of the positive arcs exceeds the first preset number.