Decoder for block-based decoding of picture data using a deblocking or deringing filter, configured to reconstruct, in a blockwise manner, a picture from a data stream using prediction and using a prediction residual coded in the data stream to obtain a reconstructed version of the picture, wherein the step of reconstructing the picture in a blockwise manner is done by partitioning the picture into blocks (181, 182, 183, 184; 181a-181g; 182a-182d) and performing the reconstruction of the picture using the blocks (181, 182, 183, 184; 181a-181g; 182a-182d), wherein the partitioning of the picture into blocks (181, 182, 183, 184; 181a-181g; 182a-182d) is performed by subjecting each of a plurality of tree root blocks (181, 182, 183, 184) into which the picture is pre-partitioned to recursive multi-tree sub-divisioning so that the blocks form leaf blocks (181a-181g; 182a-182d) of the plurality of tree-root blocks (181, 182, 183, 184), and apply the deblocking or deringing filter to the reconstructed version of the picture, and locally vary a strength of the deblocking or deringing filter depending on a first measure locally measuring for each tree root block (181, 182, 183, 184) a mean block size, and a second measure locally measuring for each tree root block (181, 182, 183, 184) a number of prediction residuals that are not fully quantized to zero, wherein the decoder is further configured to determine the first measure by determining, for each tree root block (181, 182, 183, 184), the number of leaf blocks (181a-181g; 182a-182d) into which the respective tree root block (181, 182, 183, 184) is split. reconstruct, in a blockwise manner, a picture from a data stream using prediction and using a prediction residual coded in the data stream to obtain a reconstructed version of the picture, wherein the step of reconstructing the picture in a blockwise manner is done by partitioning the picture into blocks (181, 182, 183, 184; 181a-181g; 182a-182d) and performing the reconstruction of the picture using the blocks (181, 182, 183, 184; 181a-181g; 182a-182d), wherein the partitioning of the picture into blocks (181, 182, 183, 184; 181a-181g; 182a-182d) is performed by subjecting each of a plurality of tree root blocks (181, 182, 183, 184) into which the picture is pre-partitioned to recursive multi-tree sub-divisioning so that the blocks form leaf blocks (181a-181g; 182a-182d) of the plurality of tree-root blocks (181, 182, 183, 184), and wherein the step of reconstructing the picture in a blockwise manner is done by partitioning the picture into blocks (181, 182, 183, 184; 181a-181g; 182a-182d) and performing the reconstruction of the picture using the blocks (181, 182, 183, 184; 181a-181g; 182a-182d), wherein the partitioning of the picture into blocks (181, 182, 183, 184; 181a-181g; 182a-182d) is performed by subjecting each of a plurality of tree root blocks (181, 182, 183, 184) into which the picture is pre-partitioned to recursive multi-tree sub-divisioning so that the blocks form leaf blocks (181a-181g; 182a-182d) of the plurality of tree-root blocks (181, 182, 183, 184), and apply the deblocking or deringing filter to the reconstructed version of the picture, and locally vary a strength of the deblocking or deringing filter depending on a first measure locally measuring for each tree root block (181, 182, 183, 184) a mean block size, and a second measure locally measuring for each tree root block (181, 182, 183, 184) a number of prediction residuals that are not fully quantized to zero, a first measure locally measuring for each tree root block (181, 182, 183, 184) a mean block size, and a second measure locally measuring for each tree root block (181, 182, 183, 184) a number of prediction residuals that are not fully quantized to zero, wherein the decoder is further configured to determine the first measure by determining, for each tree root block (181, 182, 183, 184), the number of leaf blocks (181a-181g; 182a-182d) into which the respective tree root block (181, 182, 183, 184) is split.