MEASURING SYSTEM FOR MEASURING A SURFACE OF AN OBJECT OR SKIN OF A PERSON

1 . A method for identifying a surface property of the skin of a person, the method comprising:

acquiring surface data of the skin of the person by activating illumination elements for illuminating the skin of the person with measuring light and capturing at least one image by detecting measuring light reflected by the skin of the person by means of a camera, and

providing a 3D model of the skin of the person by processing the surface data,

providing a virtual space,

providing the 3D model in the virtual space,

providing a virtual light source in the virtual space to virtually illuminate the 3D model with illumination light, wherein illumination parameters of the virtual light source are variable, and

virtually illuminating the 3D model by applying a set of illumination parameters.

2 . The method according to claim 1 , wherein the 3D model is provided by:

deriving a point cloud based on the surface data,

generating a 3D mesh based on the point cloud, in particular a textured 3D mesh,

identifying a set of landmarks in the 3D mesh,

providing a base template of the skin of the person to be modelled,

providing the 3D model by fusing the 3D mesh and the base template utilising the landmarks, wherein the number of meshes of the 3D mesh is maintained,

applying texturing of the 3D model with at least micro-normal texturing data related to the skin of the person, wherein the micro-normal texturing data is derived based on a specular map or based on data derived with a measuring system.

3 . The method according to claim 2 , wherein the specular map is derived by:

illuminating the object and capturing at least one diffuse image, wherein illuminating and capturing provide filtering of identical circular polarisation directions,

illuminating the object and capturing at least one reflection image, wherein illuminating and capturing provide filtering of opposite circular polarisation directions,

comparing the image data of the at least one diffuse image and the image data of the at least one reflection image, and

deriving the specular map based on the comparison of the image data.

4 . The method according to claim 1 , wherein the method provides virtually illuminating the 3D model by illuminating of wrinkles by

selecting or defining a wrinkle region in the 3D model which comprises at least one wrinkle,

defining a predominant direction which represents a predominant extension of the at least one wrinkle,

computing a region normal which represents a normal direction related to the wrinkle region, wherein the region normal corresponds to a normal vector in the centre of the wrinkle region,

orienting an illumination axis perpendicular to the predominant direction and enclosing an illumination angle (β) with the region normal, in particular wherein the illumination axis intersects the region normal, and

providing the virtual light source on the illumination axis.

5 . The method according to claim 4 , wherein the predominant direction is defined by

selecting a direction according to a pre-known wrinkle appearance in the wrinkle region, or

applying a wrinkle analysis to the 3D model according to the wrinkle region.

6 . The method according to claim 4 , wherein the region normal is derived based on an averaging a number of normal vectors related to the wrinkle region.

7 . The method according to claim 4 , wherein the illumination angle (B) is greater than 45° and/or the illumination angle is smaller than 60°.

8 . The method according to claim 7 , wherein a setting functionality for setting the illumination angle (β) is provided upon execution of which an interface, in particular an user interface, is provided to variate the illumination angle between 45° and 60° upon an input of an operator.

9 . The method according to claim 4 , wherein an optical axis of the virtual light source is aligned coaxial with the illumination axis.

10 . The method according to claim 4 , wherein the method comprises capturing the wrinkles by:

selecting or defining a viewing direction which is diametrically opposed to the region normal, the viewing direction providing generating a wrinkle image according to an optical axis parallel or coaxial to the viewing direction and facing the wrinkle region, and

generating a wrinkle image according to the viewing direction.

11 . The method according to claim 1 , wherein the virtual light source is provided by at least one of

a point light source

an elongated light source, wherein the extension direction of which is parallel to the predominant direction,

micro-illumination, wherein for each pixel an incidence angle is calculated based on an extension of the wrinkle or based on the illumination angle or a normal vector for the pixel.

12 . The method according to claim 4 , wherein an appearing state of the 3D model is determined based on the virtual illumination, and the surface property of the skin of the person is derived based on the appearing state, wherein determining the appearing state of the 3D model comprises computing an interaction of the virtual illumination of the 3D model and the micro-normal texturing data.

13 . The method according to claim 4 , wherein a first illumination of the 3D model is applied by applying a first set of illumination parameters and a first appearing state of the 3D model is determined based on the first virtual illumination,

a second illumination of the 3D model is applied by applying a second set of illumination parameters and a second appearing state of the 3D model is determined based on the second virtual illumination, and

a particular surface property of the skin of the person is identified based on comparing the first appearing state and the second appearing state.

14 . The method according to claim 13 , wherein a particular region in the 3D model is identified based on the identified particular surface property and a marker is provided with the 3D model to mark the particular region.

15 . The method according to claim 1 , wherein

the illumination parameters comprise at least one of:

a relative position of the 3D model and the virtual light source,

a wavelength of the illumination light,

a property of the illumination light, in particular regarding diffused or collimated light,

a polarisation state of the illumination light.

16 . The method according to claim 14 , wherein

the illumination parameters comprise at least one of:

a relative position of the 3D model and the virtual light source,

a wavelength of the illumination light,

a property of the illumination light, in particular regarding diffused or collimated light,

a polarisation state of the illumination light.

17 . A computer program product comprising program code for performing the method according to claim 1 .

18 . A computer program product comprising program code for performing the method according to claim 16 .