A method of encoding data includes selecting a line to define an adjustment target coefficient group in each of a plurality of coefficient groups included in a transform unit that has been transformed and quantized. Each of the coefficient groups comprises a plurality of coefficients. For each of the coefficient groups, a sum of the coefficients for the respective coefficient group is calculated. For each of the coefficient groups, a value of one adjustment target coefficient included in the adjustment target coefficient group is adjusted according to a result of the calculation of the sum of the coefficients for the respective coefficient group.