Figure 2.

Minimum RMSE penalty weights as a function of information density for the simulated Sinc+ phantom are shown. The lines show the power‐law fits of the individual penalties with RMSE‐optimal penalty weights as a function of ID for the Sinc+ phantom. The first‐ and second‐order individual penalties use the TV(1) and TV(2) prefixes, respectively (and similarly for the combined penalty using the HOTV prefixes). The dashed lines show the minimum RMSE fit for the combined penalties using the same ID ‐dependent scaling term, where the individual penalty fits provide the relative penalty weight scaling. Ten realizations over a wide range of values (see Table 1) were used (error bars smaller than marker size) for each penalty weight estimate. [Color figure can be viewed at wileyonlinelibrary.com]