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Further Analyses

Because the algorithm constructs the indicator functions as orthogonal P-dimensional vectors, one can project the original data into this signal subspace spanned by the indicator functions. If we define the projection matrix \( \mathbf{P}_{s} \) as
 


\begin{displaymath}\mathbf{P}_{s}=\Phi \Phi ^{\mathrm{T}}\end{displaymath}

then the original data projected into the signal subspace is,
 


\begin{displaymath}\mathbf{F}\mathbf{P}_{s}=\mathbf{F}\Phi \Phi ^{\mathrm{T}}=\mathbf{R}\Phi ^{\mathrm{T}}.\end{displaymath}

Therefore the KT x P matrix, \( \hat{\mathbf{F}}=\mathbf{R}\Phi ^{\mathrm{T}} \), can be considered as the ``cleaned data'', after all noise contributions have been removed. At this point, one can apply any standard analysis procedures, like averaging among all images under each experimental condition, etc.


Takeshi Yokoo 2002-03-28