The invention is a method of constructing an image of a petroleum reservoir from dynamic data having application for petroleum reservoir characterization. At least two independent realizations of the reservoir are generated from at least two Gaussian white noises. At least one region is defined within the reservoir and a parameter allowing the shape and the size of this region to be modified is defined. A new realization of the reservoir is then generated from a linear combination of the white noises. The coefficients of this linear combination depend on the parameter allowing the region to be modified. A local objective function measuring, within this region, a difference between dynamic data simulated from the new realization and the measured dynamic data is then calculated. Finally, the image of the reservoir is constructed by iteratively modifying the parameter so as to minimize the local objective function.