METHOD AND APPARATUS OF DERIVING INTRA PREDICTION MODE USING MOST PROBABLE MODE GROUP

摘要

An image encoding apparatus is presented. A differential quantization parameter is generated by subtracting a quantization parameter predictor from a quantization parameter, and is entropy-coded. If two or more quantization parameters are available among a left quantization parameter, an above quantization parameter and a previous quantization parameter of a current coding unit, the quantization parameter predictor is generated using two available quantization parameters determined according a predetermined order, and if only one quantization parameter is available, the available quantization parameter is set as the quantization parameter predictor. A transform type for inversely transforming the residual signals is selected among a discrete cosine transform (DCT)-based integer transform and a discrete sign transform (DST)-based integer transform based on a prediction mode and a size of a transform unit.

主权项

1. An image encoding apparatus comprising:
an intra prediction unit to determine an intra prediction mode of a current prediction unit and generating one or more prediction blocks using the intra prediction mode; an inter prediction unit to determine motion information and generating a prediction block; a transform unit to transform residual signals generated by using an original block and the prediction block to generate a transformed block; a quantization unit to determine a quantization parameter and quantizing the transformed block using a quantization matrix and the quantization parameter to generate a quantized block; a scanning unit to determine a scan pattern and applying the scan pattern to significant coefficients, sign flags and levels of the quantized block respectively; an entropy coding unit to entropy-code one-dimensional coefficient information received from the scanning unit, intra prediction information received from the intra prediction unit, and motion information received from the inter prediction unit; an inverse quantization unit to inversely quantize the quantized block; an inverse transform unit to inversely transform the inversely quantized block to generate residual block; an adder to generate a reconstructed block by adding the residual block and the prediction block; and a post-processing unit to remove blocking artifact in a reconstructed picture, wherein a differential quantization parameter is generated by subtracting a quantization parameter predictor from the quantization parameter, and is entropy-coded, wherein if two or more quantization parameters are available among a left quantization parameter, an above quantization parameter and a previous quantization parameter of a current coding unit, the quantization parameter predictor is generated using two available quantization parameters determined according a predetermined order, and if only one quantization parameter is available, the available quantization parameter is set as the quantization parameter predictor, and wherein a transform type for inversely transforming the residual signals is selected among a discrete cosine transform (DCT)-based integer transform and a discrete sign transform (DST)-based integer transform based on a prediction mode and a size of a transform unit.