We have described several of the systematic limitations in traditional methods of range acquisition with optical triangulation range scanners, including intolerance to reflectance and shape changes and speckle noise. By analyzing the time evolution of the reflected light imaged onto the sensor, we have shown that distortions induced by shape and reflectance changes can be corrected, while the influence of laser speckle can be reduced. In practice, we have demonstrated that we can significantly reduce range distortions with existing hardware. Although the spacetime method does not completely eliminate range artifacts in practice, it has proven to reduce the artifacts in all experiments we have conducted.
In future work, we plan to incorporate the improved range data with algorithms that integrate partial triangulation scans into complete, unified meshes. We expect this improved data to ease the process of estimating topology, especially in areas of high curvature which are prone to edge curl artifacts. We will also investigate methods for increasing the resolution of the existing hardware by registering and deblurring multiple spacetime images [9]. Finally, we hope to apply the results of scalar diffraction theory to put the achievement of speckle reduction on sound theoretical footing.
We thank the people of Cyberware for the use of the range scanner and for their help in accessing the raw video output from the range camera.