| 摘要 |
In a low-latency touch-sensitive device, post-processing is performed to convert a two-dimensional map of signal strengths into usable touch events. Four such post-processing procedures are disclosed: field flattening, touch point detection, interpolation and touch point matching between frames. The field flattening procedure subtracts an offset to remove crosstalk between rows and columns, and compensates for differences in amplitude between particular row/column combinations due to attenuation. The touch point detection procedure computes coarse touch points by finding local maxima in the flattened signal. The interpolation procedure computes fine touch points from the coarse touch points. In an embodiment, such interpolation is done by fitting the coarse touch points to a paraboloid. The frame matching procedure matches the calculated touch points to each other across frames. |
