Apparatus and method for optical inspection of a pipeline (2) for transporting fluid (3) by internal surveying. Light source means (4) are adapted to form one or more beams of light (5) illuminating a line (L) of a surface part (9) of said pipeline (2). Optical receiving means (6) are positioned outside a plane formed by said beams (5) and arranged to have in its field of view (7) the line (L) formed on the internal wall of the pipeline (2) by the beam (5). The receiving means (6) are adapted to form a two-dimensional indexed images (20_k) each comprising intensity data for a predetermined number of pixels in each of a predetermined number of lines (M) of said image (20). A data processing unit (100) including an image analyzer module (110) is adapted for extracting a depth profile of said surface (9).