1. A method for displaying a video composed of images each comprising a predetermined number M of lines and, a predetermined number N of pixels in each line, where M and N are integers, the method comprising the steps of: storing in memory values of a predetermined number P of reference pixels for each line of a current image of the video, where P is an integer that is less than N; determining, for each line of the current image, the value of a parameter associated with the line, the parameter corresponding to the number of the reference pixels of the line that are black according to a first predetermined criterion; and determining a first nonblack line and a last nonblack line of the current image to serve as a basis for an automatic reframing of the images of the video before display, the first nonblack line of the current image being determined by excluding, starting from a first line of the image, the lines of the image which are black according to a second predetermined criterion based on the parameter, and the last nonblack line of the current image being determined by excluding, starting from a last line of the image, the lines of the image which are black according to the second predetermined criterion based on the parameter.