Projection method for a motor vehicle for projecting an image onto a projection surface

Description

TECHNICAL FIELD OF THE INVENTION

[0001] The present invention relates to a method of projecting at least one image onto a projection surface for a motor vehicle by means of a light module.

[0002] It finds a particular but not limited application in lighting devices, such as motor vehicle headlights. TECHNOLOGICAL BACKGROUND OF THE INVENTION

[0003] A method for projecting at least one image known to a person skilled in the art onto a projection surface, such as a road, comprises projecting a graphic symbol understandable to the driver of the motor vehicle to assist them in driving. For example, the graphic symbol could be the speed limit not to be exceeded on the road, or the distance to another motor vehicle.

[0004] One drawback of this state of the art is that this method applies to the driver only.

[0005] EP 2233356 A1 discloses an information display device designed to allow a vehicle driver to access predetermined information without excessively taking their eyes off the road, even in the presence of ambient light, such as headlights. A lamp arrangement control device is operated such that the direction of a person deemed to be in danger and the distance to that person are displayed by a reduced-brightness area on the road surface as part of the area illuminated by the lamps.

[0006] JP 2009184428 A discloses a vehicle lighting device, comprising an image generator which processes the image by rotating the direction of the information contained in the image according to the detected position of a target object.

[0007] In this context, the present invention aims to provide a method for projecting at least one image onto a projection surface for a motor vehicle by means of a light module which is applied regardless of the observer's position relative to the motor vehicle and which thus makes it possible to obtain an image which is understandable by an observer outside the motor vehicle or which is understandable by an observer located inside the motor vehicle. GENERAL DESCRIPTION OF THE INVENTION

[0008] To this end, the invention proposes a method for projecting at least one image onto a projection surface for a motor vehicle by means of a light module adapted to project a light beam, in which said projection method comprises the steps of: detect an observer's observation position in a light module reference frame, said step consisting of considering that: when the observer is inside the motor vehicle, the observation position is at the driver's eye level; when the observer is outside the motor vehicle, said external observer, the observation position is at the eye level of said external observer; calculate the observer's observation position in an image reference frame;project said image onto said projection surface as a function of said observer's position in said image frame, said image being integrated into said light beam of the light module, in which the projection of said image comprises the sub-steps of: from a light intensity map of the light beam of the light module comprising a plurality of intensity indicators, calculate a luminance map on the projection surface resulting in luminance points; calculate the position of each luminance point in the image frame; from its position and the observer's position in said image frame, define the coordinates of the projection of each luminance point onto the image plane of said image to be projected; if said projection belongs to said image to be projected, define the coordinates of the corresponding pixel;For each projection of a luminance point belonging to said image to be projected, correct the intensity value of the corresponding intensity indicator according to the color of the corresponding pixel.

[0009] Thus, as we will see in detail below, the projection of the image to be projected depends on the observer's position and is introduced into the light beam of the light module. In this way, it is made visible and understandable to the observer, whether they are located inside the passenger compartment of the motor vehicle or outside the vehicle.

[0010] According to non-limiting embodiments, the projection process may further include one or more additional features from the following:

[0011] According to a non-limiting embodiment, the calculation of the luminance mapping on the projection surface includes the following steps: perform a first calculation of the position of said intensity indicators on the projection surface resulting in impact points; perform a second calculation of an illuminance map of said impact points; perform a third calculation of the luminance map of said impact points from the illuminance map resulting in said luminance points.

[0012] According to a non-limiting embodiment, said first calculation is based on: the position of the light module; and the direction of said intensity indicators.

[0013] According to a non-limiting embodiment, said second calculation is based on: the calculated position of the intensity indicators; the luminous intensity of said intensity indicators; and the distance between the light module and said impact points.

[0014] According to a non-limiting embodiment, the image to be projected is calculated based on properties of the projection surface.

[0015] According to a non-limiting embodiment, said third calculation is based on: the illumination of said impact points; a position vector between the position of an impact point in the illumination map and the observer's observation position; and a light scattering function.

[0016] According to a non-limiting embodiment, the calculation of the observation position of an observer and the position of a luminance point in the image reference frame is based on at least one transformation matrix from the light modulus reference frame to said image reference frame which takes into account at least one of the following parameters: the position of the image to be projected in the light module reference frame; the rotation of the image to be projected.

[0017] In a non-limiting embodiment, defining the coordinates of a projection of a luminance point includes the following substeps: calculate the point of intersection between: the line passing through the observation position in said image frame of the observer and through the position in said image frame of said luminance point; and the image plane of the image to be projected; determine the coordinates of said point of intersection from the dimensions of said image to be projected.

[0018] According to a non-limiting embodiment, the projection surface is considered as a Lambertian diffuser.

[0019] According to a non-limiting embodiment, the projection surface is a floor or a wall.

[0020] According to a non-limiting embodiment, the observer is outside the motor vehicle or is located inside said motor vehicle.

[0021] According to a non-limiting embodiment, the image appears distorted in the light module reference frame and undistorted in the image reference frame. According to a non-limiting embodiment, the calculation of the observer's observation position in the image reference frame is a function of the position and rotation of the image to be projected in the light module reference frame, said rotation being a function of a site angle greater than -90° and less than or equal to 0°; According to a non-limiting embodiment, the calculation of the position of each luminance point in the image reference frame is a function of the position and rotation of the image to be projected in the light module reference frame, said rotation being a function of a site angle greater than -90° and less than or equal to 0°; According to a non-limiting embodiment, the site angle is equal to 0.

[0022] According to a non-limiting embodiment, the site angle is substantially equal to -35°.

[0023] According to a non-limiting embodiment, the projection of each luminance point onto the image plane of said image to be projected is central, so as to produce a conical perspective effect.

[0024] According to a non-limiting embodiment, the correction of the intensity value of the intensity indicator is carried out as follows: Vi = φ Vi 0 ∗ Co / 255 , with Vi the corrected intensity value, Vi0 the initial intensity value of the intensity indicator of the light module, Co the color of the corresponding pixel, σ a maximum overintensification factor.

[0025] According to a non-limiting embodiment, the correction of the intensity value of the intensity indicator is carried out as follows: Vi = φ ⋅ Co , with Vi the corrected intensity value, φ a luminance coefficient, Co the color of the corresponding pixel.

[0026] According to a non-limiting embodiment, the observation position of an observer is calculated using a camera.

[0027] According to a non-limiting embodiment, the light intensity map is stored in a memory.

[0028] According to a non-limiting embodiment, the projection of said image onto the projection surface further comprises the substep of projecting, by means of said light module, onto the projection surface the light beam with the intensity values ​​corrected by the intensity indicators.

[0029] A lighting device for motor vehicles is also proposed, comprising a processing unit and a light module adapted to project a beam of light, in which: said processing unit is adapted to: detect an observer's observation position in a light module reference frame, considering that: when the observer is inside the motor vehicle, the observation position is at the driver's eye level; when the observer is outside the motor vehicle, referred to as the external observer, the observation position is at the eye level of said external observer; calculate the observer's observation position in an image reference frame;said lighting device is adapted to project said image onto said projection surface according to said observer's observation position in the image frame, said image being integrated into said light beam of the light module, in which, for the projection of said image onto the projection surface, said processing unit is further adapted to: from a light intensity map of the light beam of the light module comprising a plurality of intensity indicators, calculate a luminance map on the projection surface resulting in luminance points; calculate the position of each luminance point in the image frame; from its position and the observer's observation position in said image frame, define the coordinates of the projection of each luminance point onto the image plane of said image to be projected;if said projection belongs to said image to be projected, define the coordinates of the corresponding pixel; for each projection of a luminance point belonging to said image to be projected, correct the intensity value of the corresponding intensity indicator according to the color of the corresponding pixel.

[0030] According to a non-limiting embodiment, for the projection of said image onto the projection surface, the light module is adapted to project onto the projection surface the light beam with the intensity values ​​corrected by the intensity indicators.

[0031] According to a non-limiting embodiment, the lighting device is a spotlight or a rear light.

[0032] According to a non-limiting embodiment, the processing unit is integrated into the light module.

[0033] A motor vehicle is also offered that includes a lighting device according to the above characteristics. BRIEF DESCRIPTION OF THE FIGURES

[0034] The invention and its various applications will be better understood by reading the following description and examining the accompanying figures. there figure 1 represents a flowchart of the steps in the process of projecting at least one image onto a projection surface according to a non-limiting embodiment of the invention; the figure 2 represents a motor vehicle comprising a lighting device adapted to implement the projection process of the figure 1 according to a non-limiting embodiment; the figure 3 represents a light intensity map established according to a step in the projection process of the figure 1 according to a non-limiting embodiment; the figure 4represents a projector that integrates a light module and the direction of a light beam from a light module of said projector, said light module being adapted to perform at least one step of the projection process of the figure 1 ; there figure 5 represents a flowchart illustrating sub-steps of a step in establishing a luminance map of the projection process of the figure 1 according to a non-limiting embodiment; the figure 6 represents the projector of the figure 4 and a point of impact of the light beam on the ground; the figure 7 represents the projector of the figure 6 and the illumination of the point of impact; the figure 8 indicates the site angle and azimuth angle taken into account in a calculation step of the observation position of an observer in the projection process of the figure 1 ; there figure 9schematically represents a point of impact, an observation position of an observer external to the motor vehicle in an image reference frame, and an image to be projected by the projection process of the figure 1 ; there Figure 10 illustrates an image projected using the projection process of the figure 1 , an image which is seen from the point of view of the driver of said motor vehicle but which is only understandable by an observer outside the motor vehicle; the figure 11 illustrates an image projected using the projection process of the figure 1 , an image which is seen from the perspective of a rear passenger of said motor vehicle but which is only understandable by an observer outside the motor vehicle; the figure 12 illustrates an image projected using the projection process of the figure 1, an image which is seen from the point of view of said observer external to the motor vehicle and which is understandable by said observer external to the motor vehicle; the figure 13 represents a flowchart illustrating sub-steps of a step in defining the coordinates of a projection of a luminance point in the projection process of the figure 1 according to a non-limiting embodiment; the figure 14 schematically represents the point of impact, the observation position of the observer external to the motor vehicle, and the image to be projected from the figure 9 by the projection process of the figure 1 and the coordinates of the intersection between the point of impact and the image to be projected; the figure 15 schematically represents the point of impact, the observation position of the observer external to the motor vehicle, and the image to be projected from the figure 14 standardized; and the figure 16schematically represents pixels of the image to be projected from the figure 14 ; and the figure 17 illustrates a lighting system adapted to implement the projection process of the figure 1 . DESCRIPTION OF METHODS OF IMPLEMENTING THE INVENTION

[0035] Identical elements, whether structural or functional, appearing on different figures retain the same references unless otherwise specified.

[0036] The MTH projection method for motor vehicles, which projects at least one image onto a projection surface using a luminous module ML according to the invention, is described with reference to figures 1 to 16 .

[0037] By motor vehicle, we mean any type of motorized vehicle.

[0038] As illustrated on the figure 1 The MTH process includes the following steps: detect an observation position PosO1 of an observer O in a light module reference frame RP (step illustrated DET_POS(O, PosO1, RP)); calculate the observation position PosO2 of the observer O in an image reference frame RI (step illustrated DET_POS(O, PosO2, RI)); project said image Ip onto said projection surface S as a function of said observation position PosO2 of the observer O in said image reference frame RI, said image Ip being integrated into said light beam Fx of the light module ML (step illustrated PROJ(Fx, Ip, S)).

[0039] As illustrated on the figure 1 The projection of said image Ip comprises the following sub-steps: 3a) from a light intensity map CLUX of the light module ML comprising a plurality of intensity indicators pf, calculate a luminance map CLUM on the projection surface S resulting in luminance points pl (step illustrated CALC_CLUM(CLUX, S, pl)); 3b) calculate the position PosL2 of each luminance point pl in the image reference frame RI (step illustrated CALC_POS(pl, PosL2, O, RI)); 3c) from its position PosL2 and the observation position PosO2 of the observer O in said image reference frame RI, define the coordinates ply, plz of the projection plr of each luminance point pl in the image plane P1 of said image to be projected Ip (step illustrated DEF_PLR(plr, P1, PosL2, PosO2)); 3d) if said projection plr belongs to said image to be projected Ip, define coordinates lig, col of the corresponding pixel Pix (step illustrated DEF_PIX(pl(lig, col), ply, plz);3e) for each projection plr of a luminance point pl belonging to said image to be projected Ip, correct the intensity value Vi of the corresponding intensity indicator pf as a function of the color Co of the corresponding pixel Pix (step illustrated MOD_PF(pf, Vi, Pix, Co)). ;

[0040] Note that the first step, 3a in particular, as well as step 3b in particular, can be performed before the iterations of the following steps. More generally, the described steps are not necessarily performed sequentially, i.e., within the same iteration loop, but can be iterated at different times and with different iteration frequencies.

[0041] The image projection step Ip further includes a substep 3f) of projecting onto the projection surface S the light beam Fx with intensity values ​​Vi corrected by intensity indicators pf (step illustrated in the figure 1 PROJ(ML, Fx, Vi, pf)).

[0042] The MTH projection method is suitable for projecting one or more Ip images simultaneously. In the following description, the projection of a single image is used as a non-limiting example.

[0043] It should be noted that the projection can be done at the front of the motor vehicle V, at the rear or on its sides.

[0044] The ML light module allows the production of a light beam Fx, said light beam Fx comprising a plurality of light rays Rx which follow different directions.

[0045] The ML light module allows the intensity value Vi of each intensity indicator pf to be modified; it is therefore a digital light module. As described below, the image to be projected Ip is thus integrated into the light beam Fx of the ML light module.

[0046] Note that the CLUX light intensity map is discretized so that it can be used digitally.

[0047] The light module ML is considered as a point light source from which the space around said light source is discretized. Thus, an intensity indicator pf is a point in space illuminated by the light module ML that has a certain direction dir1 and a given intensity value Vi provided by the light module ML in said direction dir1. The direction dir1 is given by two angles θ and δ (described later).

[0048] In a non-limiting embodiment, the projection surface S is the floor (referenced S1) or a wall (referenced S2). The image that will be projected Ip onto the floor or wall is thus a 2D image.

[0049] In a non-limiting embodiment illustrated on the figure 2A lighting device DISP of the motor vehicle V comprises at least one light module ML and is adapted to implement the projection method MTH. In the non-limiting example shown, the lighting device is a projector.

[0050] As we will see below, the observation position of the observer O is taken into account for the projection of the image to be projected Ip. For this purpose, the image to be projected Ip will be distorted so that it is understandable by the observer in question, whether it be the driver or a front or rear passenger of the motor vehicle or an observer outside the motor vehicle.

[0051] We thus adopt the perspective of observer O, for whom we want to project the image Ip. From this observer's point of view, the image Ip will not be distorted. From a different point of view, the image Ip will be distorted.

[0052] In non-limiting examples, an observer O external to the vehicle is a pedestrian, a driver of another motor vehicle, a cyclist, a motorcyclist, etc. He may be in front of, behind, or on one of the sides of the motor vehicle V.

[0053] In a non-limiting embodiment, the projected image Ip includes at least one graphic symbol. This graphic symbol will improve the comfort and / or safety of the observer O. In a non-limiting example, if the observer O is the driver of the motor vehicle, the graphic symbol could represent the speed limit not to be exceeded on the road, a STOP graphic symbol when the motor vehicle is reversing and an obstacle (pedestrian, wall, etc.) is too close to the motor vehicle, an arrow to assist the driver when the motor vehicle is about to turn on a road, etc.

[0054] In a non-limiting example, if the observer O is outside the motor vehicle such as a pedestrian or cyclist, the graphic symbol can be a STOP sign to indicate to him that he should not cross in front of the motor vehicle because the latter will start again.

[0055] In a non-limiting example, if the observer O is outside the motor vehicle, such as a following vehicle, the graphic symbol could be a STOP sign when the motor vehicle in question brakes, prompting the driver of the following vehicle to brake as well. In another non-limiting example, if the observer O is outside the motor vehicle and is a motor vehicle overtaking from the side, the graphic symbol could be a warning symbol indicating that motor vehicle to pull back into its lane because another motor vehicle is approaching from the opposite direction.

[0056] As illustrated on the figure 2The projected image Ip is a STOP symbol. It is oriented onto the projection surface S, here the ground in the illustrated example, in such a way that the observer O can see and understand this STOP symbol. In the illustrated example, the projection is made in front of the motor vehicle V and the observer O is outside the motor vehicle V.

[0057] The various stages of the MTH projection process are described in detail below. 1)_Detection of the observer's observation position in the RP luminous module reference

[0058] To detect the observation position PosO1 of observer O in the light module frame RP, it is necessary to detect the position of observer O itself in the light module frame RP. For this purpose, in a non-limiting example, a camera (not shown) is used. It is suitable for detecting and calculating the position of an observer O located outside the motor vehicle V.

[0059] In non-limiting embodiments, the camera is replaced by a radar, or a lidar.

[0060] For an observer O located inside the motor vehicle (driver or passenger), reference observation positions are considered. Thus, in a non-limiting example, the driver's eye is considered to be located at position PosO1 (1.5; -0.5; 1) (expressed in meters) of the light module ML in the case of a car. Of course, if the motor vehicle is a truck, the position of the eye relative to the light module ML is different.

[0061] For an external observer, from the position of said observer O, we can deduce their observation position PosO1, which corresponds to the position of their eye. For example, we might place the position of their eye at approximately 1.5 meters above the ground.

[0062] Since such detection of the observer's position is known to a person skilled in the art, it is not described in detail here. 2) Calculation of the observer's observation position in the image reference frame RI

[0063] The observation position PosO1 of observer O was previously determined according to the light module reference frame RP. It will be used for the change of reference frame described below.

[0064] This step involves a change of reference frame. We move from the luminous module reference frame RP (defined by the axes pjx, pjy, pjz) to the image reference frame RI (defined by the axes lx, ly, Iz) of the image to be projected Ip.

[0065] The calculation of the observation position PosO2 of the observer O in the image frame RI is based on at least one transformation matrix M from the light modulus frame RP to said image frame RI.

[0066] In a non-limiting embodiment, the PosO2 position is of the form: pjx pjy pjz 1

[0067] In a non-limiting embodiment, said at least one transformation matrix M takes into account at least one of the following parameters: the position Poslp of the image to be projected Ip in the light modulus frame of reference RP; the rotation Rotlp of the image to be projected Ip in the light modulus frame of reference RP; the scale of the image to be projected Ip

[0068] The Poslp position of the image to be projected Ip is deduced from the light module reference frame RP according to a translation along the three axes pjx, pjy, pjz of said light module reference frame RP.

[0069] In a non-limiting embodiment, the transformation matrix M is of the form: abct defu ghiv 0001 where a, e and i are the affinity terms; b, c, d, f, g and h are the rotation terms; and t, u and v are the translation terms.

[0070] The affinity terms a, e, and i allow for enlargement or reduction of the image Ip. For example, the overall size can be increased (homothetic) by 50% or reduced by 20% by increasing the values ​​of a, e, and i by 50% and decreasing them by 20%, respectively. As an example, a value of 1 for a, e, and i corresponds to a predetermined reference dimension of the projected image, along the pjx, pjy, and pjz directions, respectively. It is also possible to apply the enlargement or reduction factors along only one dimension, or two dimensions (non-homothetic). Different enlargement or reduction factors can also be applied to some dimensions compared to others; in particular, different enlargement or reduction factors can be applied to each dimension individually.In this way, depending on the position PosO2 of the observer's eye O, we can decide to project an image that appears to the observer O larger or smaller overall or according to certain dimensions, depending on whether the values ​​of a, e and i increase or decrease respectively.

[0071] Note that the Rotlp rotation depends on three angles, which are as follows: β: azimuth (which indicates whether the image to be projected is to the right or left of the observer, for example when the latter looks to the right or left); Ω: cant (which indicates the tilt of the image to be projected Ip, for example when the observer tilts their head to the side. This is equivalent to tilting the image Ip); ε: site (which indicates the effect that we want to give to the graphic symbol of the image Ip).

[0072] There figure 8 illustrates the site angles, azimuth and plane P1 of the image to be projected Ip.

[0073] Thus, PosO2=M*PosO1.

[0074] PosO1 is the observation position of observer O used for the projection of the image Ip into the light module reference frame RP.

[0075] PosO2 is the observation position of observer O used for the projection of the image Ip into the image reference frame RI.

[0076] Thus, the position and rotation of the image to be projected Ip are adapted according to the observer O. In this way, the image to be projected Ip will be understandable by the observer O. We thus obtain an affine deformation of the image from the point of view we desire, called anamorphosis.

[0077] Thus, for the eye of a car driver, the projected image Ip is not distorted. Similarly, for the eye of a truck driver, although positioned well above the light module reference frame RP, the projected image Ip is also not distorted. Finally, for an external observer, the projected image Ip is also not distorted.

[0078] It should be noted that the projected image Ip can thus be clearly visible to the observer since its projection depends on the observer's position O and its scale can be adjusted as desired. Therefore, even if the observer O is far from the vehicle, they will still be able to understand and see the graphic symbol(s) of the projected image Ip. 3) Projection of the image lp onto the projection surface This step includes the following sound stages: 3a) Calculation of a CLUM luminance map

[0079] In a non-limiting embodiment, the CLUX light intensity map is stored in memory. It will have been previously established during the product design phase using a goniophotometer (not shown). The goniophotometer is, for example, type A, meaning that the rotational movement around the horizontal axis supports the rotational movement around the vertical axis adjusted for the rotation around the horizontal axis. The CLUX light intensity map provides the intensity indicators pf of the light module ML, considered as a point light source. The direction dir1 of a light ray Rx emanating from the light module ML is expressed as a function of two angles θ and δ and is given by the following formula: direction = cos θ ∗ cos δ sin θ cos θ ∗ sin δ

[0080] With δ the vertical rotation V of the goniophotometer; and θ the horizontal rotation H of the goniophotometer.

[0081] The CLUX light intensity map thus comprises a plurality of intensity indicators pf whose direction dir1 is given by the formula above, with θ the horizontal angle of the intensity indicator pf, and δ the vertical angle of the intensity indicator pf. The CLUX light intensity map is represented on the figure 3 We can see an intensity indicator pf with polar coordinates δ=0V, θ=0H. The CLUX light intensity map thus allows us to determine an intensity I(θ,δ) for a given direction.

[0082] Thus we have: CLUX = δ i , δ j , I i , j , i , j ϵ 1 M × 1 N , where M and N are the number of discretization points (or intensity indicators) of the light beam Fx along the (respectively) vertical and horizontal directions.

[0083] An intensity indicator pf is therefore defined by its direction dir1 and its intensity I(θ,δ).

[0084] There figure 4illustrates a DISP lighting device comprising a light module ML with the direction of a light beam Fx.

[0085] The calculation of the CLUM luminance map on the projection surface S includes the following substeps illustrated in the figure 5 . i) a first calculation of the position POSpf of said intensity indicators pf on the projection surface S resulting in impact points pi (step illustrated CALC_POSF(pf, POSpf, pi)); ii) a second calculation of an illuminance map CECL of said impact points pi (step illustrated CALC_CECL(pi, CECL)); iii) a third calculation of the luminance map CLUM of said impact points pi from the illuminance map CECL resulting in said luminance points pl (step illustrated CALC_CLUM(pi, CECL)).

[0086] The different sub-steps are detailed below.

[0087] Note that the following calculations are carried out based on the projection surface S (floor S1 or wall S2). o sub-step i)

[0088] The first calculation is based on: the position POSpj of the luminous module ML in the Cartesian coordinate system x, y, z; and the direction dir1 of the said intensity indicators pf described previously.

[0089] For ground S1, we thus obtain the position POSpf1 of the intensity indicator pf on the ground in the Cartesian coordinate system x, y, z with the following formula. POSpf 1 = POSpj - POSpj . z / dir 1 . z ∗ dir 1 .

[0090] With POSpj.z, the z value of the position of the light module ML (height of the light module above the ground) and dir1.z, the z value of the direction vector of the light ray Rx.

[0091] For wall S2, we thus obtain the position POSpf2 of the intensity indicator pf on the wall in the Cartesian coordinate system x, y, z with the following formula. POSpf 2 = POSpj - POSpj . z / dir 1 . z ∗ dir 1 .

[0092] With dir1.x, the x-value of the direction vector of the light ray Rx; D, the distance between the light module ML and the wall. In a non-limiting example, D is equal to 25 meters.

[0093] This results in an impact point pi (in position POSpf1 or POSpf2) on the ground S1 or on the wall S2. figure 6 illustrates a non-limiting example of an impact point pi on a projection surface S which is the ground S1. o sub-step ii)

[0094] Once the point of impact pi on the ground S1 or on the wall S2 is determined, the illuminance E of this point of impact pi is calculated from the intensity I(θ,δ) of the intensity indicator pf determined previously.

[0095] For ground S1, we thus obtain the irradiance ER of the point of impact pi on the ground with the following formula. E R = I θ δ / dist 1 2 ∗ cos θ ∗ cos δ

[0096] With dist1, the distance between the point of impact pi and the light module ML.

[0097] For wall S2, we thus obtain the EM illuminance of the point of impact pi on the wall with the following formula. E M = I θ δ / dist 1 2 ∗ cos θ ∗ cos δ

[0098] With dist1, the distance between the point of impact pi and the light module ML.

[0099] There figure 7 illustrates the illumination E (delimited by a dotted circle) of an impact point pi on a projection surface S which is the ground S1. o sub-step iii)

[0100] The third calculation is based on: the illumination E of said impact points pi; a position vector Roeil / Moeil between the position of an impact point pi of the CECL illumination map and the observation position PosO1 of the observer O (in the light module reference frame RP); and a light scattering function d. d is a known function that allows us to calculate the diffusion of light by the projection surface S. We will note that it varies according to the nature of the projection surface S. For example, the function d is different if the surface is asphalt, concrete, tar, paving stones etc.

[0101] For ground S1, we thus obtain the luminance LR of the point of impact pi on the ground with the following formula. L R = E R d arcos R oeil R oeil . z R oeil R oeil . z

[0102] With Roeil Roeil . z the z-value of the normalized Roeil vector.

[0103] For wall S2, we thus obtain the luminance LM of the point of impact pi on the wall with the following formula. L M = E M d arcos M oeil M oeil . x M oeil M oeil . x

[0104] With Moeil Moeil . x the x value of the normalized Moeil vector.

[0105] In a non-limiting embodiment, it is assumed that the projection surface S emits uniformly in all directions.

[0106] In this case, the diffusion parameter d does not depend on the angles δ and θ.

[0107] In a non-limiting embodiment, the projection surface S is considered a Lambertian diffuser (for example, a grey body). We then have a constant luminance on the projection surface S proportional to the illuminance E, and in this case, the diffusion function d is a cosine.

[0108] In this case, LR = a / π ER because L R = E R a π . cos acos R → oeil ⋅ z → R → oeil R → oeil ⋅ z → R → oeil = a π E R where a is the albedo of the material, and LM = a / π EM

[0109] In non-limiting examples, the albedo of asphalt is 7%, and that of concrete varies between 17% and 27%. 3b) Calculation of the positions of the luminance points pl in the image reference frame RI

[0110] The PosL1 position of a luminance point pl was previously determined according to the luminance modulus reference frame RP. It will be used for the change of reference frame described below.

[0111] Similar to the calculation of the observer's position PosO2, this step involves a change of reference frame. We move from the light modulus reference frame RP (defined by the axes pjx, pjy, pjz) to the image reference frame RI (defined by the axes Ix, ly, Iz) of the image to be projected, Ip.

[0112] The calculation of the PosL2 position of a luminance point pl in the image reference frame RI is based on said at least one transformation matrix M from the light modulus reference frame RP to said image reference frame RI (transformation matrix M described previously).

[0113] In a non-limiting embodiment, the PosL2 position is of the same form as the PosO2 position described previously: pjx pjy pjz 1

[0114] Note that the transformation matrix M was described during the calculation of the observation position PosO2 of observer O in the image frame RI. It is therefore not detailed again here.

[0115] Thus, PosL2=M*PosL1.

[0116] PosL1 is the position of the luminance point pl in the luminous modulus reference frame RP.

[0117] PosL2 is the position of the luminance point pl in the image reference frame RI.

[0118] There figure 9 illustrates the image to be projected Ip as well as the image reference frame RI. We can also see the luminance point pl and the observer's eye O (which corresponds to the observation position) with their respective positions PosL2 and PosO2 defined in the image reference frame RI.

[0119] Note that although the projected image Ip onto the ground or wall is 2D (two-dimensional), a 3D (three-dimensional) effect—that is, a perspective or trompe-l'œil effect—can be obtained by adjusting the site angle ε mentioned earlier. The observer O (whether the driver, a passenger, or an outside observer) will see the image in perspective. For this purpose, the site angle ε is greater than -90°.

[0120] In particular, it is greater than -90° and less than or equal to 0°. The 3D effect is therefore visible between 0 and up to -90° (not inclusive).

[0121] Note that at -90° the IP image is flattened to the ground and therefore has no 3D effect.

[0122] THE Figures 10 to 12 illustrate a projected image Ip, which is a pyramid. An observer O who is outside the motor vehicle, such as a pedestrian, is taken as a non-limiting example. The pyramid is visible from three particular viewpoints: the driver's viewpoint ( Figure 10), the point of view of a rear passenger ( figure 11 ) and the pedestrian's point of view ( figure 12 ), but is only seen in 3D from a single viewpoint. In the illustrated, non-exhaustive example, only the pedestrian will see the pyramid in 3D (as illustrated on the figure 12 From the driver's or passenger's point of view, the pyramid appears distorted.

[0123] In a non-limiting embodiment, the site angle ε is equal to 0. The observer O looks straight ahead. In this case, the observer O will see the image, namely the pyramid, as if it were upright.

[0124] In a non-limiting embodiment, the site angle ε is approximately equal to -35°. This allows for a 3D effect observed in the direction of the road.

[0125] The plane P1 of the image Ip is thus perpendicular to the observation direction of the observer O.

[0126] If the site angle ε is not -90°, the pyramid will be visible in 3D but more or less inclined. 3c) Define the coordinates ply, plz of the projection plr of a point of luminance pl

[0127] As illustrated on the figure 13 In a non-limiting embodiment, the definition of the coordinates ply, plz of a projection plr of a point of luminance pl comprises the substeps of: i) calculate the point of intersection Int between (illustrated substep CALC_INT(PosO2, PosL2, P1)): the line V(PosO2, PosL2) passing through the observation position PosO2 in said image frame RI of the observer O and through the position PosL2 in said image frame RI of said luminance point pl; and the image plane P1 of the image to be projected Ip. ii) determine the coordinates ply, plz of said point of intersection Int from the dimensions L1, H1 of said image to be projected Ip (illustrated substep DEF_COORD(Int, L1, H1).

[0128] These two sub-steps are described below. o sub-step i)

[0129] In the image reference frame RI, the point of intersection Int between the line (eye, luminance point) and the image plane P1 is the point on the line (eye, luminance point) for which lx = 0. Thus, we have: Int = PosO 2 - PosO 2 . x / V ( PosO 2 , PosL 2 . x ∗ V PosO 2 , PosL 2 With V(PosO2, posL2) is the vector representing the line (eye, luminance point) in the image frame RI; V(PosO2, posL2).x is the value x of the vector; Int is the point of intersection between the line (eye, pl) and the image to be projected Ip in the image frame RI. The point of intersection Int is thus the projection plr of the luminance point pl onto the image plane P1 of the image to be projected lp; PosL2.x is the value x of the position of the luminance point pl; PosO2.x is the value x of the observer's observation position.

[0130] Note that we assume that the observation position of observer O is placed on the lx axis.

[0131] There figure 14This illustrates the image to be projected, Ip, the point of intersection, Int, which corresponds to the projection plr of the luminance point pl onto the plane P1, and the vector V(posO2, posL2) (shown as a dashed line). Note that the projection plr is central, so as to produce a conical perspective effect. Hereafter, the terms plr projection and central plr projection will be used interchangeably. o sub-step ii)

[0132] The coordinates ply, plz of the central projection plr of the luminance point pl in the image frame RI correspond to the coordinates along the ly axis (vertical) and along the Iz axis (horizontal) of the position of the intersection point Int determined previously. In a non-limiting embodiment, they are expressed in meters.

[0133] From this, we deduce the coordinates of this point in the coordinate system of the figure 14 using the following formulas: ply = Int . y + L 1 / 2 / L 1 plz = Int . z / H 1 With, L1 the width of the image to be projected Ip (expressed in meters in a non-limiting example); H1 the height of the image to be projected Ip (expressed in meters in a non-limiting example); Int.y the y value of the intersection point; Int.z the z value of the intersection point.

[0134] There figure 14 illustrates the definition of ply and plz coordinates in meters in the RI image reference frame.

[0135] Note that L1 and H1 are input parameters of the MTH projection process.

[0136] This sub-step allows us to determine later whether the coordinates ply, plz belong to the image to be projected Ip (they must then be between 0 and 1) and therefore whether the central projection plr of the point of luminance pl belongs to the image to be projected Ip.

[0137] To this end, in a non-limiting embodiment, the image to be projected, Ip, and the projection coordinates thus calculated, plr, are normalized. This simplifies the test for belonging to the image to be projected, Ip.

[0138] This gives us a normalized coordinate system with IX (vertical axis) and IY (horizontal axis), as illustrated on the... figure 15 The values ​​of the coordinates ply, plz of the projection plr are now between 0 and 1. In the illustrated example, the axes ly and Iz have become the axes IX and -IY, respectively. This results in image dimensions H2, L2 between 0 and 1.

[0139] There figure 15 illustrates the definition of ply and plz coordinates in unitless values ​​in the image reference frame RI.

[0140] Note that the size (L1, H1) of the image to be projected Ip can be defined in this step 3c) or in the step with the transformation matrix M.

[0141] Given that the dimensions L1 and H1 and therefore L2, H2, the position and rotation of the image to be projected Ip are known (these are input parameters of the MTH projection process), we can easily determine, via its coordinates ply, plz, whether the projection pl belongs or not to the image to be projected Ip. • 3d) Define the coordinates of the corresponding pixel Pix

[0142] The definition of the row (lig), column (col) coordinates of the pixel Pix is ​​carried out for each projection plr (of luminance point pl) which belongs to the image to be projected Ip, namely which is located inside the rectangle L2*H2 of the image to be projected Ip, which was verified in step 3c-ii).

[0143] Thus, if the projection plr belongs to the image to be projected Ip, the coordinates of the corresponding pixel Pix are calculated. They are calculated as follows. Lig = − plz * L 2 Col = ply * H 2 With, lig, the row of the pixel; col, the column of the pixel; L2 the width of the image to be projected Ip (this time expressed in pixels); H2 the height of the image to be projected Ip (this time expressed in pixels); ply the coordinate of the projection plr along the IX axis; plz the coordinate of the projection plr along the IY axis. 3e) Correction of the intensity value of the corresponding intensity indicator pf

[0144] With the coordinates lig, col of the pixel Pix, we can retrieve the value of its color Co in the image we want to project.

[0145] In a non-limiting example, the value ranges from 0 to 255. This allows for a range from white to black, passing through several shades of gray, as illustrated in the... figure 16The term "white" should be understood as any single color, and the expression "shades of gray" should be understood as the shades of that single color between its lightest shade and black. Thus, the projected image is not necessarily composed of the color white and the shades of gray associated with Co values ​​between 0 and 255, but rather of the darker or lighter shades of any color visible to the human eye. Advantageously, these are white, yellow, blue, red, or amber.

[0146] We then correct the intensity value Vi of the corresponding intensity indicator pf.

[0147] It should be noted that this is possible because the ML light module is digitized.

[0148] In a first, non-limiting embodiment, the correction is carried out as follows: Vi = σ . Vi 0 * Co / 255 . With : Vi0 is the initial intensity value of the intensity indicator pf of the light module, Co is the color of the corresponding pixel Pix; and σ is a maximum overintensification factor.

[0149] In a second, non-limiting embodiment, the correction is carried out as follows: Vi = δ ⋅ . Co , where φ is a luminance coefficient. This performs a luminance substitution. This allows the image to be displayed on a background independent of the basic light distribution.

[0150] This step is performed for all luminance points pl whose central projection plr belongs to the rectangle L2*H2 of the image to be projected Ip.

[0151] Thus, the ML light module can project onto the projection surface S the light beam Fx comprising the light rays Rx with intensity values ​​Vi corrected by the intensity indicators (step 3f) illustrated on the figure 1PROJ(ML, Fx, pf, Vi). This allows the correct color Co to be displayed for the considered intensity indicator. In this way, the image to be projected Ip is integrated into the light beam Fx of the light module ML (since it is produced by said light module ML itself) and is projected onto the projection surface S with the correct colors.

[0152] Thus, depending on the desired color Co of a pixel Pix, a specific correction factor is applied to the intensity value Vi of the corresponding intensity indicator pf. This allows us to obtain intensity indicators whose color does not depend on the luminous intensity of the light beam Fx itself. For example, the projected pyramid shown is of uniform color.

[0153] In the case of a light source independent of the ML light module that projects the pyramid superimposed onto the light beam, this would not be the case. The image pixels would be more or less illuminated depending on the distribution of the light intensity of the beam. Their color would thus vary according to the light intensity of the beam.

[0154] Furthermore, the fact that the image to be projected, Ip, is integrated into the light beam, Fx, and not superimposed on it, results in better image contrast on the projection surface, S, than when using a separate light source. With a separate light source, the beam also illuminates the projected image, resulting in a brighter color image.

[0155] It should be noted that the color value Co of a pixel, or a series of pixels corresponding to predetermined parts of the projected image, can also be used to enhance the 3D effect. For example, with reference to the figure 12 The pixels corresponding to face F1 of the projected image pattern and those corresponding to face F2 of the projected image pattern can have specific and different color values ​​(Co). Thus, face F1 appears brighter than face F2, or vice versa, depending on whether the Co value corresponding to the pixels composing face F1 is higher or lower than that corresponding to the pixels composing face F2. The Co value corresponding to the pixels composing face F1 and / or F2 can also vary to create a gradient effect, for example, from one edge to the other of face F1 and / or F2, further enhancing the 3D effect.

[0156] It is possible to obtain multicolor images by using several systems operating according to the process described above, each emitting a visually distinct color. The images projected by each system are then calculated to be superimposed on the projection surface S to obtain a single, multicolor projected image.

[0157] It should be noted that, since the projection of the image to be projected, Ip, depends on the observer's position, O, it is therefore continuously updated according to the observer's movement relative to the vehicle when the observer is outside the vehicle, and according to the vehicle's movement itself when the observer is inside the vehicle. In a non-limiting embodiment, the refresh rate of the calculations presented above is thus a function of the observer's speed relative to the vehicle in the case of an external observer. The higher the speed, the higher the refresh rate. The lower the speed, the lower the refresh rate.

[0158] In another non-limiting embodiment, the refresh rate of the calculations presented above is constant. In a non-limiting example, the frequency is one second.

[0159] Thus, since these calculations are performed in real time, it is not necessary to have a database with images of the same graphic symbol pre-loaded in memory corresponding to several imaginable observation positions of the observer relative to the motor vehicle (when outside), or inside the motor vehicle (when inside).

[0160] The MTH projection process thus makes it possible to project one or more images Ip onto a projection surface S which is not only visible to an observer located inside or outside the motor vehicle but also understandable to him since the projected image Ip is oriented in the direction of the gaze of said observer O.

[0161] Note that in the case where several images Ip are projected at the same time, the combination of the different images with the light beam Fx is calculated before projecting the overall result.

[0162] In a non-limiting embodiment, the MTH projection process is implemented by a DISP lighting device for motor vehicle V.

[0163] In a non-limiting embodiment, the DISP lighting device enables the performance of a regulatory photometric function such as a dipped beam, main beam, or a front, rear, and / or side signaling function. Thus, the lighting device is located at the front or rear of the motor vehicle.

[0164] The DISP lighting device is illustrated in the figure 17It comprises a PR processing unit and at least one ML lighting module. In non-limiting embodiments, the lighting device is a spotlight or a rear light.

[0165] The PR treatment unit is suitable for: detect an observation position PosO1 of an observer O in a light module reference frame RP (function illustrated DET_POS(O, PosO1, RP)); calculate the observation position PosO2 of the eye of the observer O in an image reference frame RI (function illustrated DET_POS(O, PosO2, RI));

[0166] The said lighting device DISP is adapted to project said image Ip onto said projection surface S as a function of said observation position PosO2 of the observer O in the image reference frame RI, said image Ip being integrated into said light beam Fx of the light module ML (function illustrated PROJ(Fx, Ip, S).

[0167] For projecting said image Ip onto said projection surface S, the processing unit PR is further adapted for: from a light intensity map CLUX of the light module ML comprising a plurality of intensity indicators pf, calculate a luminance map CLUM on the projection surface S resulting in luminance points pl (function shown CALC_CLUM(CLUX, S, pl)); calculate the position PosL2 of each luminance point pl in the image reference frame RI (function shown CALC_POS(pl, PosL2, O, RI)); from its position PosL2 and the observation position PosO2 of the observer O in said image reference frame RI, define the coordinates ply, plz of the projection plr of each luminance point pl on the image plane P1 of said image to be projected Ip (function shown DEF_PLR(plr, P1, PosL2, PosO2)); if said projection plr belongs to said image to be projected Ip, define coordinates lig, col of the corresponding pixel Pix (function illustrated DEF_PIX(pl(lig, col), ply, plz));for each projection plr of a luminance point pl belonging to said image to be projected Ip, correct the intensity value Vi of the corresponding intensity indicator pf as a function of the color Co of the corresponding pixel Pix (function illustrated MOD_PF(pf, Vi, Pix, Co)); ;

[0168] For the projection of said image Ip onto the projection surface S, the light module ML is adapted to project onto the projection surface S the light beam Fx with the intensity values ​​VI corrected by the intensity indicators pf (function illustrated PROJ(ML, Fx, Vi, pf)).

[0169] It should be noted that the PR processing unit is either integrated into the ML light module or is independent of said ML light module. Of course, the description of the invention is not limited to the embodiments described above.

[0170] Thus, in another non-limiting embodiment, a type B goniophotometer can also be used, i.e., the rotational movement around the vertical axis supports the rotational movement around the horizontal axis.

[0171] Thus, in another non-limiting embodiment, the PR processing unit may be located remotely from the DISP lighting device.

[0172] Thus, the step of calculating the observation position PosO2 in the image reference RI can be carried out before or at the same time as the calculation of the luminance position PosL2.

[0173] Thus, the motor vehicle V includes one or more DISP lighting devices adapted to implement the MTH projection process described.

[0174] Thus, the described invention offers the following advantages in particular: It allows the projection of an image containing at least one graphic symbol that improves the comfort and / or safety of an observer inside or outside the motor vehicle; it allows the projection of an image that is visible and understandable to a specific observer because the projection depends on the observer's position. The same projection method is applied to project an image understandable by the driver, a pedestrian, or the driver of a following vehicle, for example. It also allows the image to be distorted (Ip) so that it is understandable to a specific observer. This creates an anamorphic image, the anamorphic nature of which depends on the observer's position (O). The observer's position in the image frame is a function of the position and rotation of the image to be projected.Thanks to the rotation, which depends in particular on a specific elevation angle, the observer has the impression of seeing a 3D image when this angle is set in a particular way. This allows the information to be projected to be integrated into the Fx light beam of the vehicle's ML light module. No additional dedicated light source is required. Thus, unlike prior art that displays an image directly onto the lens of the vehicle's rear light, which can appear too small at a certain distance, the invention allows an external observer at a certain distance from the vehicle to clearly see the image, since it is projected according to the observer's position and onto a projection surface that is not the lens of a vehicle light.The dimensions of the image to be projected Ip are no longer limited to the small projection surface such as the lens of the light; it allows us to offer a solution that can be used for a recipient of the information who can only see the front or sides of the motor vehicle, for example, unlike a solution that displays an image on the rear lights of the motor vehicle; it allows us to offer an alternative to displaying image(s) on the rear lights of the motor vehicle; it allows us to offer an alternative to projecting image(s) solely for the driver of the motor vehicle.

Claims

1. Projection method (MTH) for a motor vehicle (V) of at least one image (Ip) on a projection surface (S) by means of a light module (ML) of a motor vehicle adapted to project a light beam (Fx), said projection method (MTH) comprising the following steps: - detecting an observation position (PosO1) of an observer (0) in a light module reference frame (RP), said step consisting in considering that: • when the observer (0) is inside the motor vehicle, the observation position is at the level of the driver's eye; • when the observer (0) is outside the motor vehicle, said external observer, the observation position is at the level of the eye of said external observer; - calculating the observation position (PosO2) of the observer (0) in an image reference frame (RI); - projecting said image (Ip) on said projection surface (S) according to said observation position (PosO2) of the observer (0) in said image reference frame (RI), said image (Ip) being integrated in said light beam (Fx) of the light module (ML), characterized in that the projection of said image (Ip) includes the substeps of: • from a light intensity map (CLUX) of the light beam (Fx) of the light module (ML) comprising a plurality of intensity indicators (pf), calculating a luminance mapping (CLUM) on the projection surface (S) resulting in luminance points (pl); • calculating the position (PosL2) of each luminance point (pl) in the image reference frame (RI); • from its position (PosL2) and the observation position (PosO2) of the observer (0) in said image reference frame (RI), defining the coordinates (ply, plz) of the projection (pIr) of each luminance point (pl) on the image plane (P1) of said image to be projected (Ip); • if said projection (plr) belongs to said image to be projected (Ip), defining coordinates (lig, col) of the corresponding pixel (Pix); • for each projection (plr) of a luminance point (pl) belonging to said image to be projected (Ip), correcting the intensity value (Vi) of the corresponding intensity indicator (pf) according to the color (Co) of the corresponding pixel (Pix).

2. Projection method (MTH) according to the preceding claim, wherein the calculation of the luminance mapping (CLUM) on the projection surface (S) comprises the steps of: - performing a first calculation of the position (POSpf) of said intensity indicators (pf) on the projection surface (S) resulting in impact points (pi); - performing a second calculation of an illumination mapping (CECL) of said impact points (pi); - performing a third calculation of the luminance mapping (CLUM) of said impact points (pi) from the illumination mapping (CECL) resulting in said luminance points (pl).

3. Projection method (MTH) according to the preceding claim, wherein said first calculation is based on: CLAIMS - the position (POSpj) of the light module (ML); and - the direction (dir1) of said intensity indicators (pf).

4. Projection method (MTH) according to claim 2 or claim 3, wherein said second calculation is based on: - the calculated position (POSpf) of the intensity indicators (pf); - the light intensity (I(0,8)) of said intensity indicators (pf); and - the distance (dist1) between the light module (ML) and said impact points (pi).

5. Projection method (MTH) according to any one of the preceding claims, wherein the image to be projected is calculated according to properties of the projection surface.

6. Projection method (MTH) according to the preceding claim, taken in combination with any one of the preceding claims 2 to 4, wherein said third calculation is based on: - the illumination (E) of said impact points (pi); - a position vector (Roeil) between the position of an impact point (pi) of the illumination mapping (CECL) and the observation position (PosO1) of the observer (O); and - a light diffusion function (d).

7. Projection method (MTH) according to any one of the preceding claims, wherein the calculation of the observation position (PosO2) of an observer (O) and the position of a luminance point (pl) in the image reference frame (RI) is based on at least one transformation matrix (M) from the light module reference frame (RP) to said image reference frame (RI) that takes into account at least one of the following parameters: - the position (Poslp) of the image to be projected (Ip) in the light module reference frame (RP); - the rotation (Rotlp) of the image to be projected (Ip).

8. Projection method (MTH) according to any one of the preceding claims wherein the definition of the coordinates (ply, plz) of a projection (plr) of a luminance point (pl) comprises the sub-steps of: - calculating the intersection point (Int) between: • the line passing through the observation position (PosO2) in said image reference frame (RI) of the observer (0) and through the position (PosL2) in said image reference frame (RI) of said luminance point (pl); and • the image plane (P1) of the image to be projected (Ip); - determining the coordinates (ply, plz) of said intersection point (Int) from the dimensions (L1, H1) of said image to be projected (Ip).

9. Projection method (MTH) according to any one of the preceding claims, wherein the projection surface (S) is a floor or a wall.

10. Projection method (MTH) according to any one of the preceding claims, wherein the calculation of the observation position (PosO2) of the observer (O) in the image reference frame (RI) is a function of the position (Poslp) and the rotation (Rotlp) of the image to be projected (Ip) in the light module reference frame (RP), said rotation (Rotlp) being a function of a site angle (e) greater than -90° and less than or equal to 0°.

11. Projection method (MTH) according to any one of the preceding claims, wherein the calculation of the position (PosL2) of each luminance point (pl) in the image reference frame (RI) is a function of the position (Poslp) and the rotation (Rotlp) of the image to be projected (Ip) in the light module reference frame (RP), said rotation (Rotlp) being a function of a site angle (e) greater than -90° and less than or equal to 0°.

12. Projection method (MTH) according to any one of the preceding claims, wherein the correction of the intensity value (Vi) of the intensity indicator (pf) is performed as follows: Vi = σ. Vi0*Co / 255, with Vi the corrected intensity value, Vi0 the initial intensity value of the intensity indicator (pf) of the light module (ML), Co the color of the corresponding pixel (Pix), σ a maximum over-intensification factor.

13. Projection method (MTH) according to any one of the preceding claims, wherein the correction of the intensity value (Vi) of the intensity indicator (pf) is performed as follows: Vi=o.Co, with Vi the corrected intensity value, o a luminance coefficient, Co the color of the corresponding pixel (Pix).

14. Projection method (MTH) according to any one of the preceding claims, wherein the projection of said image (Ip) on the projection surface (S) further includes the sub-step of projecting by means of said light module (ML) on the projection surface (S) the light beam (Fx) with the corrected intensity values (Vi) of the intensity indicators (pf).

15. Lighting device (DISP) of a motor vehicle (V) comprising a processing unit (PR) and a light module (ML) adapted to project a light beam (Fx), wherein: - said processing unit (PR) is adapted to: • detect an observation position (PosO1) of an observer (O) in a light module reference frame (RP) considering that: ✔ when the observer (O) is inside the motor vehicle, the observation position is at the level of the driver's eye; ✔ when the observer (O) is outside the motor vehicle, said external observer, the observation position is at the level of the eye of said external observer; • calculate the observation position (PosO2) of the observer (O) in an image reference frame (RI); - said lighting device (DISP) is adapted to project said image (Ip) on said projection surface (S) according to said observation position (PosO2) of the observer (O) in the image reference frame (RI), said image (Ip) being integrated in said light beam (Fx) of the light module (ML), characterized in that for the projection of said image (Ip) on the projection surface (S), said processing unit (PR) is further adapted to: - from a light intensity map (CLUX) of the light beam (Fx) of the light module (ML) comprising a plurality of intensity indicators (pf), calculate a luminance mapping (CLUM) on the projection surface (S) resulting in luminance points (pl); - calculate the position (PosL2) of each luminance point (pl) in the image reference frame (RI); - from its position (PosL2) and the observation position (PosO2) of the observer (O) in said image reference frame (RI), define the coordinates (ply, plz) of the projection (plr) of each luminance point (pl) on the image plane (P1) of said image to be projected (Ip); - if said projection (plr) belongs to said image to be projected (Ip), define coordinates (lig, col) of the corresponding pixel (Pix); - for each projection (plr) of a luminance point (pl) belonging to said image to be projected (Ip), correct the intensity value (Vi) of the corresponding intensity indicator (pf) according to the color (Co) of the corresponding pixel (Pix).

16. Lighting device (DISP) according to the preceding claim, wherein for the projection of said image (Ip) on the projection surface (S), the light module (ML) is adapted to project on the projection surface (S) the light beam (Fx) with the corrected intensity values (Vi) of the intensity indicators (pf).

17. Lighting device according to claim 15 or according to claim 16, wherein the lighting device is a projector or a rear light.

18. Motor vehicle comprising a lighting device according to any one of claims 15 to 17.