A method for measuring a distance separating a camera from a reference object including a predetermined number of corners arranged in a pattern and at least two reference points separated by a reference length. The method includes acquiring an image including the reference object with the camera, detecting corners in the image, attributing a class to each corner, based on an orientation of the corner, detecting the reference object in the image based on the corners and attributed classes, placing the reference points in the image based on the corners of the reference object and measuring an imaged length separating the reference points, and comparing the reference length to the imaged length and obtaining the distance separating the camera from the reference object.