Fig. 2.

Pixel to background contrast ratio images of the absorption and reduced scattering maps at 808 nm at ${\rho }_8$ (in ${\mathrm{mm}}^{-1}/{\mathrm{mm}}^{-1}$ units). (a) Images were captured by manually raster scanning the surface of the phantom within a $12\mathrm{cm}\times 12\mathrm{cm}$ defined perimeter. The background was calculated by averaging the data using 1 cm squares at the four corners of the image. (b) Sparse-sampled data simulating a 1-cm grid image as captured in a discrete grid acquisition. Only one of two pinholes were detected (circled) due to the location of the sampling points.