Method for generating a density image of an observation area traversed by individuals over a given time interval, in which method a plurality of images of the observation area are acquired by means of a camera, and the following steps are carried out for each acquired image: - extracting a fixed background of the image, - a step a) of detecting "blob" pixel areas that stand out from the fixed background of the image, - a step b) of detecting individuals, in which: b1) for each blob, multiple hypotheses of possible positions of individuals within a three-dimensional model of the observation area are generated using the characteristics of the camera and a standard individual size; and for each possible position, a visible point of an individual is detected by applying a three-dimensional individual model to the corresponding blob, b2) counting the individuals for each blob, c) for each detected individual, determining the elementary surfaces occupied by this individual, characterized in that said step b) of detecting individuals further comprises processing said visible point of an individual to establish consistency between head and foot positions, consisting of: - establishing a correspondence between pixels of the image and points of the corresponding space, - considering that the pixels of a blob corresponding to a visible point of an individual potentially correspond to his feet or his head, and - projecting these pixels onto the ground planes and planes placed at standard head height, the common projection area of the feet and the head being identified as a possible position, the method further comprising a step of generating a density image on which the elementary surfaces thus determined are incremented by an intensity level. - extracting a fixed background of the image, - a step a) of detecting "blob" pixel areas that stand out from the fixed background of the image, - a step b) of detecting individuals, in which: b1) for each blob, multiple hypotheses of possible positions of individuals within a three-dimensional model of the observation area are generated using the characteristics of the camera and a standard individual size; and for each possible position, a visible point of an individual is detected by applying a three-dimensional individual model to the corresponding blob, b2) counting the individuals for each blob, b1) for each blob, multiple hypotheses of possible positions of individuals within a three-dimensional model of the observation area are generated using the characteristics of the camera and a standard individual size; and for each possible position, a visible point of an individual is detected by applying a three-dimensional individual model to the corresponding blob, b2) counting the individuals for each blob, - establishing a correspondence between pixels of the image and points of the corresponding space, - considering that the pixels of a blob corresponding to a visible point of an individual potentially correspond to his feet or his head, and - projecting these pixels onto the ground planes and planes placed at standard head height, the common projection area of the feet and the head being identified as a possible position,