Table 1. Maximum reconstructed absorption (cm⁻¹) (mean ± standard deviation) for phantom.

	Newton with zero Ini	Newton with PINV ini	CG with zero ini	CG with PINV ini	CG unconstrained
Reconstructed μa (low contrast)	$0.097\pm 0.018$	$0.099\pm 0.016$	$0.093\pm 0.012$	$0.100\pm 0.017$	$0.107\pm 0.069$
Reconstructed μa (high contrast)	$0.191\pm 0.042$	$0.229\pm 0.021$	$0.191\pm 0.041$	$0.228\pm 0.021$	$0.222\pm 0.027$