There is disclosed apparatuses, methods and computer program products for coding and decoding and specifically but not only for coding and decoding of image and video signals. It is determined whether two adjacent blocks of pixels of an image have a flat nature. The result of the determining is used to select a filter among at least a first filter and a second filter for filtering a block boundary between two adjacent blocks of pixels. The second filter is selected when said determining indicates that there are two adjacent blocks of pixels having a flat nature. At least a first reference value and a second reference value are selected for the second filter and used in filtering the block boundary.