Patent ID: 9264712
Filing Date: 2016-02-16
CPC Classification: H03M,H04N

Claim Text:
1. An image decoding method using arithmetic decoding, the image decoding method comprising: performing arithmetic decoding on a first flag that indicates whether or not an absolute value of a target coefficient in a target coefficient block is greater than 1; and performing arithmetic decoding on a second flag that indicates whether or not the absolute value is greater than 2, wherein, in the performing of the arithmetic decoding on the first flag and the performing of the arithmetic decoding on the second flag, it is determined whether or not an immediately-prior coefficient block that has been decoded immediately prior to the target coefficient block includes a coefficient having an absolute value greater than a threshold value, and a context to be used in the arithmetic decoding on the first flag and a context to be used in the arithmetic decoding on the second flag are selected based on a result of the determination.