| 摘要 |
The most difficult problem in the creation of a range image with stereo cameras is the establishing of the correspondence of the points. For this, the scene is illuminated twice; thereof at least once with a random or pseudo random pattern. For both cameras, an image is taken for each of the illuminations and the quotient of brightnesses is calculated pixelwise. The correspondence is established on the basis of a comparison of the quotient of pixels on epipolar lines of different cameras. The illumination pattern is preferably highly modulated along the epipolar line; transversally or diagonally to it, it is not or only slightly modulated. For illumination, a projection unit is used which in a preferred arrangement comprises two superposed grating patterns which have a distance (d) to each other, with at least one varying in a pseudo random manner, and with two closely neighboring light sources which shine through the gratings and thereby generate different pseudo random patterns, especially moiré patterns. Applications are found, inter alia, in assembly control, robotics, metrology, archaeology, in the textile industry, in biometry, medicine, reverse engineering. |
