A method for estimating the distance between a position of an observer and a target, using at least one image generated by a digital image generator from the position of the observer, characterized in that it comprises a sequence of steps comprising: - a detection and identification step consisting in detecting and identifying at least one target in the image, from at least one list of known targets, and in defining an imaged representation of the identified target; and - a distance estimation step comprising: • a projection sub-step (E2A) consisting in performing on the image a plurality of different projections of a three-dimensional model of said identified target in order to obtain projected representations (29, 30) of the target, said projected representations (29, 30) depending on characteristics of the image generator, each of said projected representations (29, 30) being representative of an associated distance of the target and an associated orientation of the target; • a comparison sub-step (E2B) consisting in comparing the imaged representation of the target to each of said projected representations (29, 30), the comparison sub-step (E2B) consisting in assigning a score to each of said projected representations (29, 30) according to the quality of the match, the quality of the match corresponding to the measure of the integration, along the outline of the projected representation (29, 30), of the distance between the outline of the imaged representation and the outline of said projected representation (29, 30); and • a selection sub-step (E2C) consisting in selecting the projected representation with the best score, the distance associated with that selected projected representation representing said estimated distance between the position of the observer and the target. - a detection and identification step consisting in detecting and identifying at least one target in the image, from at least one list of known targets, and in defining an imaged representation of the identified target; and - a distance estimation step comprising: • a projection sub-step (E2A) consisting in performing on the image a plurality of different projections of a three-dimensional model of said identified target in order to obtain projected representations (29, 30) of the target, said projected representations (29, 30) depending on characteristics of the image generator, each of said projected representations (29, 30) being representative of an associated distance of the target and an associated orientation of the target; • a comparison sub-step (E2B) consisting in comparing the imaged representation of the target to each of said projected representations (29, 30), the comparison sub-step (E2B) consisting in assigning a score to each of said projected representations (29, 30) according to the quality of the match, the quality of the match corresponding to the measure of the integration, along the outline of the projected representation (29, 30), of the distance between the outline of the imaged representation and the outline of said projected representation (29, 30); and • a selection sub-step (E2C) consisting in selecting the projected representation with the best score, the distance associated with that selected projected representation representing said estimated distance between the position of the observer and the target. • a projection sub-step (E2A) consisting in performing on the image a plurality of different projections of a three-dimensional model of said identified target in order to obtain projected representations (29, 30) of the target, said projected representations (29, 30) depending on characteristics of the image generator, each of said projected representations (29, 30) being representative of an associated distance of the target and an associated orientation of the target; • a comparison sub-step (E2B) consisting in comparing the imaged representation of the target to each of said projected representations (29, 30), the comparison sub-step (E2B) consisting in assigning a score to each of said projected representations (29, 30) according to the quality of the match, the quality of the match corresponding to the measure of the integration, along the outline of the projected representation (29, 30), of the distance between the outline of the imaged representation and the outline of said projected representation (29, 30); and • a selection sub-step (E2C) consisting in selecting the projected representation with the best score, the distance associated with that selected projected representation representing said estimated distance between the position of the observer and the target.