An apparatus for decoding images, the apparatus comprising: an intra prediction module for generating a prediction block using an intra prediction mode of a current block; an inverse scanning module for generating a quantization block by inverse scanning quantization coefficient information obtained from a received bit stream, wherein a scanning type used for inverse scanning is determined based on the intra prediction mode of the current block; an inverse quantization module for inversely quantizing the quantization block using quantization parameter; an inverse transform module for inversely transforming the inversely quantized block to reconstruct a residual block; and an addition module for creating a reconstructed block by adding the prediction block to the residual block, wherein the quantization parameter is generated, by the inverse quantization module, using a quantization parameter predictor and a residual quantization parameter, and the quantization parameter predictor is generated using quantization parameter of a left coding unit and quantization parameter of a top coding unit of a current coding unit, wherein the intra prediction mode is derived using a most probable mode, MPM, group constructed by the intra prediction module, an intra prediction mode group indicator obtained from the bit stream and an prediction mode index obtained from the bit stream, wherein an intra prediction mode indicated by prediction mode index in the MPM group is determined as the intra prediction mode of the current block when intra prediction mode group indicator indicates usage of the MPM group, wherein the MPM group includes 3 intra prediction modes which are determined by using available intra prediction mode of left and top neighboring blocks of the current block, wherein when only one of intra prediction modes of the left and the top neighboring blocks of the current block is available, the MPM group includes the only one available intra prediction mode of the left and the top neighboring blocks of the current block and two intra prediction modes are added, wherein the MPM group includes the intra prediction modes of the left and the top neighboring blocks of the current block and planar mode when one of the intra prediction modes of the left and the top neighboring blocks of the current block is DC mode and the other one of the intra prediction modes of the left and the top neighboring blocks of the current block is not planar mode, and wherein the MPM group includes planar mode, DC mode, and vertical mode when intra prediction mode of the left neighboring block of the current block is same as intra prediction mode of the top neighboring block of the current block, and the intra prediction mode of the left neighboring block of the current block is DC mode. an intra prediction module for generating a prediction block using an intra prediction mode of a current block; an inverse scanning module for generating a quantization block by inverse scanning quantization coefficient information obtained from a received bit stream, wherein a scanning type used for inverse scanning is determined based on the intra prediction mode of the current block; an inverse quantization module for inversely quantizing the quantization block using quantization parameter; an inverse transform module for inversely transforming the inversely quantized block to reconstruct a residual block; and an addition module for creating a reconstructed block by adding the prediction block to the residual block, wherein the quantization parameter is generated, by the inverse quantization module, using a quantization parameter predictor and a residual quantization parameter, and the quantization parameter predictor is generated using quantization parameter of a left coding unit and quantization parameter of a top coding unit of a current coding unit, wherein the intra prediction mode is derived using a most probable mode, MPM, group constructed by the intra prediction module, an intra prediction mode group indicator obtained from the bit stream and an prediction mode index obtained from the bit stream, wherein an intra prediction mode indicated by prediction mode index in the MPM group is determined as the intra prediction mode of the current block when intra prediction mode group indicator indicates usage of the MPM group, wherein the MPM group includes 3 intra prediction modes which are determined by using available intra prediction mode of left and top neighboring blocks of the current block, wherein when only one of intra prediction modes of the left and the top neighboring blocks of the current block is available, the MPM group includes the only one available intra prediction mode of the left and the top neighboring blocks of the current block and two intra prediction modes are added, wherein the MPM group includes the intra prediction modes of the left and the top neighboring blocks of the current block and planar mode when one of the intra prediction modes of the left and the top neighboring blocks of the current block is DC mode and the other one of the intra prediction modes of the left and the top neighboring blocks of the current block is not planar mode, and wherein the MPM group includes planar mode, DC mode, and vertical mode when intra prediction mode of the left neighboring block of the current block is same as intra prediction mode of the top neighboring block of the current block, and the intra prediction mode of the left neighboring block of the current block is DC mode.