Seismic interpretation is often complicated by a high level of noise in the seismic data, and significant geological features may be missed or misunderstood. We present a very simple and fast method to improve the quality of the structural information of a seismic cube, based on correlation of a trigonometric interpolation of the seismic data. Each point of the seismic cube is stacked with its similar neighbours along the dip of the seismic reflectors. By applying the filter iteratively, we improve the continuity of the seismic horizons without smoothing the vertical edges. By contrast, faults are also highlighted. Filtered seismic data are more explicit for interpretation by geologists and improve significantly autotracking results.