A scaling apparatus for scaling data arrays, such as images, comprises first horizontal scaling stage circuitry operable to scale a data array input to the scaling apparatus in the horizontal direction, one or more line memories for storing horizontal lines for a data array, wherein the or each line memory is for storing a horizontal line of data for the data array, vertical scaling stage circuitry operable to read data stored in the one or more line memories and to scale the read data in the vertical direction, and second horizontal scaling stage circuitry operable to scale a data array in the horizontal direction.