1. A method for characterizing a geological formation traversed by a first borehole, the method comprising: a) retrieving one or more sets of measured data provided by at least one measuring tool along one or more logged borehole length for one of the first borehole, at least one other borehole or both in order to produce a borehole imaging log, wherein the borehole imaging log has a lateral dimension corresponding to a borehole circumferential direction, wherein the measured data along the lateral dimension is disposed along a plurality of angular sectors covered by electrodes of the at least one measuring tool, and wherein data gaps exist in the borehole imaging log along the lateral dimension between the angular sectors covered by the electrodes of the at least one measuring tool; b) selecting depth-defined intervals of the borehole imaging log as training images for inputting in a multi-point geostatistical model; c) determining pattern based simulations for each training image using at least one pixel-based template of the multi-point geostatistical model so as to obtain training image patterns; d) using the pattern based simulation of each training image to assign to each of the training images a corresponding training image pattern; e) constructing from the training image patterns one or more fullbore image logs of a borehole wall of the first borehole, wherein constructing the one or more fullbore image logs includes simulating patterns in the data gaps in the borehole imaging log along the lateral dimension; and f) repeating steps (b) to (e) through the one or more logged borehole length in order to construct fullbore images from successive, adjacent training images.