Abstract: Active 3D triangulation-based imaging comprises steps of: temporally modulating a radiant flux of a lighting unit beam by a binary modulation signal (ms); illuminating a scene (S), which is illuminated by an ambient lighting (AL), by said modulated lighting unit beam (mlub); splitting a ray (ir) imaging a scene point (SP) into two separate imaging rays (ir1, ir2); said first separate imaging ray (ir1) forming an image in a first image sensor (is1); temporally modulating a radiant flux of the second separate imaging ray (ir2) by the modulation signal (ms) and said modulated second separate imaging ray (ir2m) forming an image in a second image sensor (is2); normalizing a first scene image being an image of all points of the scene (S) formed in the first sensor (is1) and a second scene image formed in the second sensor (is2); and subtracting the first normalized scene image from the second normalized scene image.