Left panel: example of the dereddening algorithm for the star with ID = 578 in the R10 catalog. The star is represented in the CMD by a regularly gridded 2D Gaussian density distribution, and to each grid element it corresponds a stripe of the galactic model (represented in dots) parallel to the reddening direction. Dereddened candidates for the outlined grid point are coded with colors from yellow to red according to increasing A_V. Central panel: cumulative distribution F(A_V) for the colored synthetic galactic stars in the left panel. For each A_V, this function represents the fraction of candidate dereddened photometries with extinction  ≤ A_V. Right panel: weighted probability density function f(A_V) of the 40 000 probabilistic A_V estimates for the representative case shown in the left panel, computed using a Gaussian kernel. The weighted mean of the sample (dashed vertical line) is our best estimate of the true extinction affecting the star.