In open CV Why is the default phase phase Gabor 90 degrees?

Question

This is used by default ( CV_PI*0.5, ) phase shift getGaborKernel(size, 8.0, 0.0, 16.0, 1.0);

The zero phase getGaborKernel(size, 8.0, 0.0, 16.0, 1.0, 0.0);

Thus, it seems that the default phase offset (90 degrees) eliminates the symmetry of the Gabor core. I saw several other links where they use the same offset, so I assume its standard conversion.

Why is this the default value? Is it generally more useful to have this for function extraction?

Also asked about opening a CV Q & A site.

Answer 1

I think, yes, the first case is more useful than the second. Because the first filter is an edge detector, and the second is a linear detector. You can create a linear detector from two edge detectors.

So, the ribs are more useful (a more general case) for the feature extractor, so I believe that a 90 degree phase shift is the default setting.