A method of processing display data, the method being implemented by an electronic data processing device, said display data being representative of at least one item of information to be displayed on a screen, said method comprising: - a step for obtaining at least one reference image (IRef) formed by a set of pixels representative of said at least one item of information to be displayed; - a step of generating , from said reference image (IRef), a plurality of degraded images (ID1, ..., IDn) using a degraded image generator (Usk), each degraded image being obtained by adding noise to the reference image (IRef) so that the value of each pixel of each degraded image follows the following expression: Dt x y = A thr F T x y in which: - Dt (x,y) represents the value of the pixel with coordinates (x,y) in the degraded image Dt; - thr is a probabilistic generator defined by thr(r) <- 1 Rnd()<r with Rnd() a probabilistic generator returning a random or pseudorandom number between 0 and 1, thr returning 1 if Rnd() < r and 0 otherwise ; - F is a contrast function; - T(x,y) represents the value of the pixel with coordinates (x,y) in the reference image noted T, - A represents an allocation value depending on the reference image (IRef), A being equal to a predetermined value representative of a pixel or equal to T(x,y) and the contrast function being defined as: F x = αx + β 255 α + β + γ Wherein: α is a density control parameter of the degraded image; β is a contrast control parameter; and γ is noise level control parameter; and - a step for displaying the plurality of degraded images on a screen. - a step for obtaining at least one reference image (IRef) formed by a set of pixels representative of said at least one item of information to be displayed; - a step of generating , from said reference image (IRef), a plurality of degraded images (ID1, ..., IDn) using a degraded image generator (Usk), each degraded image being obtained by adding noise to the reference image (IRef) so that the value of each pixel of each degraded image follows the following expression: Dt x y = A thr F T x y in which: - Dt (x,y) represents the value of the pixel with coordinates (x,y) in the degraded image Dt; - thr is a probabilistic generator defined by thr(r) <- 1 Rnd()<r with Rnd() a probabilistic generator returning a random or pseudorandom number between 0 and 1, thr returning 1 if Rnd() < r and 0 otherwise ; - F is a contrast function; - T(x,y) represents the value of the pixel with coordinates (x,y) in the reference image noted T, - A represents an allocation value depending on the reference image (IRef), A being equal to a predetermined value representative of a pixel or equal to T(x,y) and the contrast function being defined as: F x = αx + β 255 α + β + γ Wherein: α is a density control parameter of the degraded image; β is a contrast control parameter; and γ is noise level control parameter; and - Dt (x,y) represents the value of the pixel with coordinates (x,y) in the degraded image Dt; - thr is a probabilistic generator defined by thr(r) <- 1 Rnd()<r with Rnd() a probabilistic generator returning a random or pseudorandom number between 0 and 1, thr returning 1 if Rnd() < r and 0 otherwise ; - F is a contrast function; - T(x,y) represents the value of the pixel with coordinates (x,y) in the reference image noted T, - A represents an allocation value depending on the reference image (IRef), A being equal to a predetermined value representative of a pixel or equal to T(x,y) and the contrast function being defined as: F x = αx + β 255 α + β + γ Wherein: α is a density control parameter of the degraded image; β is a contrast control parameter; and γ is noise level control parameter; and α is a density control parameter of the degraded image; β is a contrast control parameter; and γ is noise level control parameter; and - a step for displaying the plurality of degraded images on a screen. <EOS>