Patent ID: 9596487
Date: 2017-03-14
CPC Classifications: H03M,H04N

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