Ascertainment of predistortion data for a projection and projector module

A method for ascertaining predistortion data for a projection of an image content from a projector in an interior of a vehicle onto a target surface of the interior, wherein geometry data of the target surface are known, and the projector is situated in an appropriate assembled state (M) in the interior, comprising:

• placing a camera in a known relative pose (RKP) with respect to the projector, wherein the camera is aligned such that at least part of the target surface lies within the field of view of the camera,
• recording a camera image using the camera,
• ascertaining the relative pose of the camera with respect to the target surface (RKZ) from the camera image by means of machine vision,
• ascertaining the relative pose (RPZ) of the projector with respect to the target surface from the relative pose (RKZ) of the camera to the target surface and from the relative pose (RKP) of the camera to the projector,
• ascertaining the actual predistortion data based on the geometry data of the target surface and on the relative pose (RPZ) of the projector with respect to the target surface, and
• wherein the camera is aligned such that at least part of the environment of the target surface is situated in the field of view of the camera and the geometry data of the environment captured by the camera in relation to the target surface is known, and wherein characteristic structures of the environment of the target surface, which structures are depicted in the camera image, are detected by means of machine vision such that information of said structures in the environment of the target surface, is additional to, and distinct from, the information received from the target surface, wherein said information is obtained and evaluated using machine vision, and wherein said characteristic structures are located outside of an object that has the target surface,
• wherein said characteristic structures of the environment of the target surface are selected from at least one of peripheries, lines, edges, trims, handles of a storage compartment, air exists, lamps and combinations thereof,
• wherein each of said characteristic structures of the environment of the target surface is additional to, and distinct from, the elements of the target surface and each characteristic structure is located outside of an object that has the target surface,
• wherein machine vision is used to determine the relative pose of the camera to the characteristic structures,
• wherein the relative pose of the target surface to the target surface environment is known from CAD data, as the target surface is fixed within the target surface environment,
• wherein the characteristic structures are identified within the camera image and only said structures are evaluated by machine vision, as the relative pose of the characteristic structures to the target surface is known from CAD data, and
• wherein the relative pose of the camera to the target surface is thereafter calculated using the determined relative pose of the camera to the characteristic structures in addition to the relative pose of the characteristic structures to the target surface which is known, thereby ascertaining the relative pose of the camera to the target surface by such calculation.