Please note that the output of the RieszGenerator is a std::vector of output images.
The RieszRotationMatrix is a itkVariableSizeMatrix, so you can get the resulting matrix with rieszRotationMatrix.GetVnlMatrix().
The problem raised by @PierreFontaine is that we do not provide any method to apply the RieszRotationMatrix to the output of the RieszGenerator.
RieszRotationMatrix, as already documented, provides a way to transform an input physical rotation matrix into a matrix that can be used to steer riesz components generated from the RieszFrequencyFilterBankGenerator.
Please note that the output of the RieszGenerator is a std::vector of output images. The RieszRotationMatrix is a itkVariableSizeMatrix, so you can get the resulting matrix with rieszRotationMatrix.GetVnlMatrix().
The problem raised by @PierreFontaine is that we do not provide any method to apply the RieszRotationMatrix to the output of the RieszGenerator.
A new method should be provided to do this.