and the best abundance estimates in terms of MSE. The abundance estimation performance of the different models is also decreasing with increasing nonlinear mixing effects in the images, even though the RE remained almost constant for NM and PPNM. FM performed poorly and LMM and GBM lead to similar results.

  ---- ------- -------------------------------------------------------- -------------------------------------------------------- -------------------------------------------------------- --------------------------------------------------------
        $0.2$                           $0.4$                                                    $0.6$                                                    $0.8$                           
        $0.8$                           $0.6$                                                    $0.4$                                                    $0.2$                           
   \*    LMM                        $   0.92    $                                            $   1.78    $                                            $   1.84    $                                            $   0.88    $
        o-LMM                       $   2.11    $                                            $   4.37    $                                            $   5.36    $                                            $   3.15    $
         FM                         $   1.37    $                                            $   3.33    $                                            $   4.56    $                                            $   3.39    $
        o-FM                        $   7.01    $                                            $   20.54   $                                            $   33.03   $                                            $   24.56   $
         NM                    $   {\mathbf{0.23}}   $                   $   {\textcolor[rgb]{0.00,0.00,1.00}{\mathbf{0.11}}} $   $   {\textcolor[rgb]{0.00,0.00,1.00}{\mathbf{0.10}}} $   $   {\textcolor[rgb]{0.00,0.00,1.00}{\mathbf{0.12}}} $
         GBM                        $   0.92    $                                            $   1.78    $                                            $   1.84    $                                            $   0.88    $
        PPNM    $   {\textcolor[rgb]{0.00,0.00,1.00}{\mathbf{0.13}}} $                  $   {\mathbf{0.15}}   $                                  $   {\mathbf{0.14}}   $                                  $   {\mathbf{0.12}}   $
   \*    LMM                        $   0.73    $                                            $   2.44    $                                            $   4.98    $                                            $   3.18    $
         FM                         $   1.43    $                                            $   5.16    $                                            $   11.65   $                                            $   14.95   $
         NM     $   {\textcolor[rgb]{0.00,0.00,1.00}{\mathbf{0.25}}} $   $   {\textcolor[rgb]{0.00,0.00,1.00}{\mathbf{0.58}}} $   $   {\textcolor[rgb]{0.00,0.00,1.00}{\mathbf{0.66}}} $                  $   {\mathbf{0.45}}   $
         GBM                        $   0.72    $                                            