1. A method for segmenting fingers, said segmentation method being implemented by a segmentation device comprising a processing unit, an acquisition device intended to capture an image of said fingers when they pass in front of said acquisition device in a direction of advancement and a projection device intended to project a sight having an isointensity axis on said fingers, said segmentation method comprising: a capture step during which the acquisition device captures an image of the fingers and of the sight, a computing step during which the processing unit computes the unrolled phase image from the image of the sight thus captured, a derivation step during which, for each pixel of the phase image thus computed, the processing unit computes the derivative of the phase along the isointensity axis of the sight, and a regionalisation step during which the processing unit associates each pixel where the derivative of the phase has been computed with a region grouping all the adjoining pixels step by step where the derivative of the phase has the same polarity, and a recognition step during which the location of each finger is recognised from the analysis of the regions thus determined.