Methods for dip determination from an image obtained by a down-hole imaging tool. For each pixel forming the image, a probability that a symmetry axis coincides with the pixel is determined. A probability map is then generated, depicting the determined probability of each pixel coinciding with the symmetry axis. The probability map and the image are then superposed to generate a mapped image. The symmetry axis is then estimated based on the mapped image. Image pixels coinciding with a boundary of the geologic feature are then selected in multiple depth zones, and a segment of a sinusoid is fitted to the selected image pixels within each depth zone. Dip within each of the depth zones is then determined based on the fitted sinusoid segments therein.