An encoder which encodes image information includes memory and circuitry accessible to the memory. The circuitry binarizes a data value indicating the number of non-zero coefficients included in a current basic block which is one of one or more basic blocks in a frequency transform block, according to a conversion table, to encode the image information which includes the data value. When binarizing the data value, the circuitry selects the conversion table from a plurality of tables including two or more tables which differ from each other in difference between a longest bit length and a shortest bit length of a plurality of binary values associated with a plurality of data values, according to the position of the current basic block in the current frequency transform block which is the frequency transform block including the current basic block, and binarizes the data value according to the conversion table selected.