Method and system for acquiring a three-dimensional shape description

DETAILED DESCRIPTION The present invention provides a method for acquiring a three-dimensional shape or image of a scene, wherein a predetermined pattern is projected onto the scene and the shape is acquired on the basis of the relative deformations of the pattern as detected in one or more images.
The invention further provides a system for acquiring a three-dimensional shape or image of a scene, including: at least one pattern generator for projecting a pattern on the scene; at least one camera for making an image or images of the scene; computing means for determining the shape of the scene.
The required hardware is simple and the system according to the present invention is therefore not very expensive.
According to the present invention it is no longer required to individually identify components of the projected pattern, such as lines or dots, either via a code in the pattern itself or via limitations imposed by the scene and/or the arrangement or a priori knowledge in respect thereof.
In the method according to the present invention the shape can be acquired via the relative positions of the components in the pattern, for instance by determining the relative sequence of pattern lines.
According to the present invention a single image will suffice to acquire a three-dimensional image or a three-dimensional shape description and an acquisition time is required which is no longer than that for making a single image.
Because the recording time of a single image can remain limited and since reconstructions can be performed for a quick succession of different images, moving objects and their three-dimensional movements and changes of shape can be reconstructed.
According to the present invention the calibration procedure can be kept simple and few limitations need be imposed on the relative position of the pattern generator(s) and camera(s).
According to the present invention the projected pattern can be kept very simple and strongly interlinked, such as for instance a grid of lines.
Owing to the simplicity, the resolution of the pattern and thereby of the three-dimensional reconstruction can be kept high