Logarithmic ratio of filament distances, log(Δd_fil) = log(d_filled/d_unfilled), for all galaxies in the COSMOS field. Here, d_filled is the distance to the nearest filament measured after in-painting the survey masks, while d_unfilled is measured without correcting for masked regions. Negative values occur near masked areas, where artificial gaps in the galaxy distribution lead to underestimated distances, whereas positive values appear farther from masks. For visualisation purposes, the colour bar is clipped to [ − 0.3, 0.3], but the actual values can exceed this range. The mean of this ratio across the field is indicated in the top right (0.027). All redshift slices are stacked, taking the average filament distance per galaxy for each measurement method.