Method of deriving quantization parameter with differential and predicted quantization parameters

摘要

Provided is a method that restores a differential quantization parameter of a current coding unit, generates a quantization parameter predictor of the current coding unit using one or two quantization parameters of a left quantization parameter, an above quantization parameter and a previous quantization parameter and generates a quantization parameter of the current coding unit using the differential quantization parameter and the quantization parameter predictor, wherein a minimum size of quantization unit is adjusted per picture. Therefore, the complexity of the encoding and decoding apparatus is reduced by adjusting the minimum size of the quantization unit. Also, coding efficiency is improved by encoding the quantization parameter using neighboring quantization parameters and by signaling the minimum size of the quantization unit per picture.

主权项

1. A method of inversely quantizing a quantized block, the method comprising:
restoring a differential quantization parameter; generating a quantization parameter predictor; generating a quantization parameter using the differential quantization parameter and the quantization parameter predictor; and inversely quantizing the quantized block using the quantization parameter and a quantization matrix, wherein the differential quantization parameter is restored using a bin string indicating an absolute value of the differential quantization parameter and a bin indicating a sign of the differential quantization parameter, 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 to a predetermined order, the quantization parameter is restored per quantization unit, and a minimum size of the quantization unit is adjusted by a picture parameter set, and the quantized block is generated by inversely scanning significant flags, coefficient signs and coefficient levels according to an inverse scan pattern which is selected based on an intra prediction mode and a size of a transform unit.