| 摘要 |
The most difficult problem when creating a distance image using stereo cameras (4, 5) is establishing correspondence between the points. To this end, the scene (3) is illuminated twice, at least once with a random or pseudorandom pattern. An image is recorded for each of the illumination operations for both cameras (4, 5) and the quotient of the brightnesses is calculated pixel by pixel. Correspondence is established on the basis of a comparison of the quotient of pixels on epipolar lines of different cameras (4, 5). The illumination pattern is preferably highly modulated along the epipolar line and is not modulated or is slightly modulated transversely to said line. For the purpose of illumination, the preferred arrangement used is a projection unit (9) having two superimposed grid patterns (21, 22) which are at a distance (d) from one another, at least one of which varies in a pseudorandom manner, and having two light sources (25, 26) which are close to one another, shine through the grids (21, 22) and in the process produce different pseudorandom patterns, in particular moiré patterns. Applications include, inter alia, assembly control, robotics, metrology, archaeology, the clothing industry, biometry, medicine, reverse engineering. |
