17 March 2015 Crosstalk characterization of PMD pixels using the spatial response function at subpixel level
Author Affiliations +
Time-of-Flight cameras have become one of the most widely-spread low-cost 3D-sensing devices. Most of them do not actually measure the time the light needs to hit an object and come back to the camera, but the difference of phase with respect to a reference signal. This requires special pixels with complex spatial structure, such as PMD pixels, able to sample the cross-correlation function between the incoming signal, reflected by the scene, and the reference signal. The complex structure, together with the presence of in-pixel electronics and the need for a compact readout circuitry for both pixel channels, suggests that systematic crosstalk effects will come up in this kind of devices. For the first time, we take profit of recent results on subpixel spatial responses of PMD pixels to detect and characterize crosstalk occurrences. Well-defined crosstalk patterns have been identified and quantitatively characterized through integration of the inter-pixel spatial response over each sensitive area. We cast the crosstalk problem into an image convolution and provide deconvolution kernels for cleaning PMD raw images from crosstalk. Experiments on real PMD raw images show that our results can be used to undo the lowpass filtering caused by crosstalk in high contrast image areas. The application of our kernels to undo crosstalk effects leads to reductions of the depth RMSE up to 50% in critical areas.
© (2015) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Miguel Heredia Conde, Miguel Heredia Conde, Klaus Hartmann, Klaus Hartmann, Otmar Loffeld, Otmar Loffeld, "Crosstalk characterization of PMD pixels using the spatial response function at subpixel level", Proc. SPIE 9393, Three-Dimensional Image Processing, Measurement (3DIPM), and Applications 2015, 93930L (17 March 2015); doi: 10.1117/12.2083353; https://doi.org/10.1117/12.2083353

Back to Top