| 摘要 |
An image decoding apparatus according to the present invention comprises: an intra prediction unit for generating a prediction block by reconstructing the intra prediction mode of the current block, in current block or sub-block of the current block units; a reverse scanning unit for transforming residual signals into a two-dimensional quantization block; a reverse quantization unit for reverse quantizing the quantization block using a quantization parameter; and a reverse transformation unit for reverse transforming the reverse quantization block. The quantization parameter predictor, used to reconstruct the quantization parameter, is generated by using the quantization parameters of the coding units left and above the current coding unit (CU). Therefore, the image quality is improved by adaptively controlling the quantization parameters on the basis of the encoding size, and the efficiency of image compression is improved by efficient encoding and decoding of the quantization parameters which reduce the number of bits necessary for transmitting quantization parameters. |
