1. A method of processing seismic image of the subsurface, said seismic image comprising pixels, each pixel having a color value, wherein the method comprises: determining a first surface and a second surface in the seismic image, the first surface and the second surface being determined based on geological information extracted from well data from at least one well in the subsurface; determining first dip components for pixels of the first surface and second dip components for pixels of the second surface; for each pixel of the seismic image between the first surface and the second surface, determining interpolated dip components based on at least the first dip components and the second dip components, for each pixel of the seismic image between the first surface and the second surface, determining an interpolated surface based on at least the interpolated dip components for pixels between the first surface and the second surface; for each current pixel of the seismic image between the first surface and the second surface, determining a density value based on a number of intersections of the determined surfaces with a column comprising said current pixel, said intersections being below said pixel in said column; determining a geological-time image, columns of said geological-time image is computed based: on the density values of pixels of as corresponding column of the seismic image; and on the color value of pixels of the corresponding column of the seismic image.