An encoding device includes an encoding unit that encodes image data, a computing unit that calculates a target amount of picture code for each picture when the image data is encoded, a selection unit that selects an adjustment coefficient corresponding to the position of a picture within a unit of image processing from adjustment coefficients that have an alternating sequence of maximum values and minimal values, and an adjusting unit that adjusts the target amount of picture code by multiplying the target amount of picture code calculated by the computing unit by the adjustment coefficient selected by the selection unit.