1. A method for detecting an object in an image having a gray-level distribution, characterized in that said method comprises the steps of: a)for a subset of pixels in said image, deriving a first variable from said gray-level distribution of said image, b)for said subset of pixels, deriving a second variable from a preset reference distribution, said reference distribution being characteristic of said object;. c)evaluating the correspondence between said first variable and said second variable over the subset of pixels; and d)determining if said image contains said object based on the result of the evaluation step.