Illustration of the FilDReaMS method applied to one pixel i of the H₂ column density map of the Herschel G210 field. Top left: initial map A of the entire G210 field. Top middle: smoothed map B obtained by convolving map A with a 2D top-hat kernel. Top right: corresponding binary map C in which the yellow pixels have a value of 1 and the dark pixels a value of 0. Bottom right: subregion C_i of map C centered on pixel i, with the model bar (width W_b, length L_b, and orientation angle ψ_b) overplotted in green. Bottom middle: measured orientation function, equal to the fraction of the bar area covered by yellow pixels, , as a function of ψ_b, (blue curve). Also shown are the ideal orientation function, (orange curve; see Sect. 3.4) and the angular window of width ∆ψ (Eq. (1)). Bottom left: subregion A_i of map A centered on pixel i, with the model bar overplotted in green at the orientation angle (ψ_f)_i of a potential filament (corresponding to the peak of ).