An image segmenting method includes: reading (202) an image, determining (232) a solution to the problem of maximum flow in a graph including, on the one hand, as vertices, a source, a sink and image points, with each point being assigned a capacity, called a through-capacity, assigning (234), on the basis of the determined solution, a label to each of at least some of the points of the image, and recording the image with the assigned labels in a computer memory. In addition, before determining a solution to the problem of maximum flow, the method includes: determining (212) critical points, for each of which, the points of the image located in a predetermined window applied around the critical point verify a predetermined condition on their through-capacities. The points of the graph include the determined critical points and the inter-point arcs link the neighboring critical points to one another.