1. An apparatus ( 100 ) for enhancing at least a region of an input picture (P_in) having input pixel values, comprising: an estimation unit ( 102 ) arranged to estimate a quantization precision (QP) of at least the region of the input picture; a pattern analysis unit ( 104 ), arranged to determine positions in the input picture of changes in input pixel value of less than or equal to the quantization precision (QP), and to output analysis information (INF_AN) representing the positions; and an adaptive filter ( 106 ), arranged to calculate an output picture (P_out) corresponding to at least the region of the input picture, comprising output pixels being determined on the basis of adaptive combinations of input pixels, and arranged to determine the adaptive combinations in dependence on the analysis information.