cout=projkern(cin,a); cout=projkern(cin,g,a); cout=projkern(cin,ga,gs,a);
| cin | Input coefficients |
| g | analysis/synthesis window |
| ga | analysis window |
| gs | synthesis window |
| a | Length of time shift. |
| cout | Output coefficients |
cout=projkern(cin,a) projects a set of Gabor coefficients c onto the space of possible Gabor coefficients. This means that cin and cout synthesize to the same signal. A tight window generated from a Gaussian will be used for both analysis and synthesis.
The rationale for this function is a follows: Because the coefficient space of a Gabor frame is larger than the signal space (since the frame is redundant) then there are many coefficients that correspond to the same signal.
Therefore, you might desire to work with the coefficients cin, but you are in reality working with cout.
cout=projkern(cin,g,a) does the same, using the window g for analysis and synthesis.
cout=projkern(cin,ga,gs,a) does the same, but for different analysis ga and synthesis gs windows.