Patent ID: 9264723
Filing Date: 2016-02-16
CPC Classification: H04N

Claim Text:
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, 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 to a predetermined order, wherein if the quantization matrix is a user-defined quantization matrix, the quantization matrix is restored by using an inverse differential pulse code modulation (DPCM), and wherein if the quantization matrix is larger than the restored quantization matrix, the quantization matrix is restored by up-sampling the restored quantization matrix.