A decoding method of creating a reconstructed block, the method comprising: obtaining an intra prediction mode group indicator and a prediction mode index from a received bit stream; decoding an intra prediction mode using the intra prediction mode group indicator, the prediction mode index and a most probable mode, MPM, group, wherein the MPM group is generated using intra prediction modes of left and top blocks of a current block, and the MPM group includes three intra prediction modes; constructing, by an intra prediction module, a prediction block using the intra prediction mode and reference pixels; inversely quantizing, by an inverse quantization module, a received residual signal using a quantization parameter to create a quantized block and inversely transforming the quantized block to create a residual block, wherein the quantization parameter is generated by adding a quantization parameter predictor to a residual quantization parameter, and wherein the quantization parameter predictor is created using a quantization parameter of a left coding unit of a current coding unit and a quantization parameter of a top coding unit of the current coding unit; and adding, by an addition module, the prediction block and the residual block to create a reconstructed block, and wherein an intra prediction mode of the current block is determined as an intra prediction mode indicated by the prediction mode index in the MPM group when the intra prediction mode group indicator indicates the MPM group, and the intra prediction mode of the current block is determined out of intra prediction modes other than the three intra prediction modes in the MPM mode group using the three intra prediction modes in the MPM mode group and the prediction mode index when the intra prediction mode group indicator does not indicate the MPM group, wherein when the intra prediction modes of the left and top blocks are not equal to each other and non-directional intra prediction modes, the MPM group includes the intra prediction modes of the left and top blocks and a vertical mode, wherein the non-directional intra prediction mode are a planar mode and a DC mode. obtaining an intra prediction mode group indicator and a prediction mode index from a received bit stream; decoding an intra prediction mode using the intra prediction mode group indicator, the prediction mode index and a most probable mode, MPM, group, wherein the MPM group is generated using intra prediction modes of left and top blocks of a current block, and the MPM group includes three intra prediction modes; constructing, by an intra prediction module, a prediction block using the intra prediction mode and reference pixels; inversely quantizing, by an inverse quantization module, a received residual signal using a quantization parameter to create a quantized block and inversely transforming the quantized block to create a residual block, wherein the quantization parameter is generated by adding a quantization parameter predictor to a residual quantization parameter, and wherein the quantization parameter predictor is created using a quantization parameter of a left coding unit of a current coding unit and a quantization parameter of a top coding unit of the current coding unit; and adding, by an addition module, the prediction block and the residual block to create a reconstructed block, and wherein an intra prediction mode of the current block is determined as an intra prediction mode indicated by the prediction mode index in the MPM group when the intra prediction mode group indicator indicates the MPM group, and the intra prediction mode of the current block is determined out of intra prediction modes other than the three intra prediction modes in the MPM mode group using the three intra prediction modes in the MPM mode group and the prediction mode index when the intra prediction mode group indicator does not indicate the MPM group, wherein when the intra prediction modes of the left and top blocks are not equal to each other and non-directional intra prediction modes, the MPM group includes the intra prediction modes of the left and top blocks and a vertical mode, wherein the non-directional intra prediction mode are a planar mode and a DC mode.