Fig. 6.

(Color online) Decay curve of singular values (log-scale) as a function of their order i for two FMT forward model matrices corresponding to weakly diffused photons (0–200 ps time-gate) as well as steady-state signal. The decay rate for the weakly diffuse photons is significantly less favorable to noise propagation in the images. (b) Illustration of some image-singular modes for the same two forward models. At the same order, the spatial frequency of the modes associated with weakly diffused photons is typically smaller than those associated with steady-state signal, again affording more leeway in reconstructing high-spatial-resolution images.