| 摘要 |
A signal processor in a touch-sensitive apparatus generates a 2D representation of touch interaction on a touch surface by tomographic processing. The signal processor generates (50, 52) observed values for detection lines that correspond to signal propagation paths across the touch surface. The observed values correspond to sampling points in a sample space defined by first and second dimensions. The first dimension represents a rotation angle of the detection line on the touch surface, and the second dimension represents a distance of the detection line from a predetermined origin on the touch surface. The signal processor processes (54) the observed values, by interpolation in the sample space, to generate estimated values for matched sampling points in the sample space, the estimated values being processed (56) by a tomographic reconstruction function. The matched sampling points are arranged to form consecutive columns that are spaced in the first dimension in the sample space. At least a subset of the consecutive columns are non-equispaced and arranged to coincide with alignment lines that are defined by the locations of the sampling points in the two-dimensional sample space. |
