|RESPITE: The CASA Toolkit Page: Documentation: Block Library Index:Delta|
The Delta block performs temporal differentiation of the input signal.
The differentiated signal, d, is computed from the input signal, c, using the following regression formula:
where d(t) is a delta value at time t computed in terms of the corresponding input values c(t-N) to c(t+N). The value of N is set using the parameter DELTA_WIN, and defaults to 2.
Since computation of the delta values relies on a window of data around the current input frame, some modification is needed at the very beginning and end of the signal. In this implementation for t<N d(t)=d(N) and the signal will be truncated by N frames at the end.
|Inputs||Meaning||Sample||1-D frame||2-D frame|
|out1||data after differentiation|
|DELTA_WIN||Integer||2||Half size of the regression window|