Method and apparatus for encoding and decoding image by using large transformation unit

An image decoding apparatus comprising:

• a processor which determines coding units having a hierarchical structure for decoding an image, at least one prediction unit for predicting each of the coding units, and at least one transformation unit for inversely transforming each of the coding units, by using information about a division shape of a coding unit, information about the at least one prediction unit, and information about the at least one transformation unit, parsed from a received bitstream of an encoded video;
• and
• a decoder which parses from the bitstream transformation coefficients generated by transformation according to the at least one transformation unit generated by dividing the coding unit, reconstructs encoded data of the at least one prediction unit by performing entropy decoding, inverse quantization, and inverse transformation on the parsed transformation coefficients, and performs intra prediction or inter prediction on the reconstructed encoded data and reconstructing the encoded video,
• wherein the coding units are split hierarchically according to a depth of the coding unit, and
• wherein the at least one transformation unit comprises a transformation unit having a larger size than a size of the at least one prediction unit.