Patent ID: 9609316
Date: 2017-03-28
CPC Classifications: H04N

Claim:
1. An image coding apparatus, comprising: a plurality of predictive coding units configured to predictively encode inputted image data; a plurality of entropy coding units configured to execute processing of both entropy encoding the image data predictively-coded by the predictive coding units on the basis of context parameters and updating the context parameters on the basis of a result of the entropy coding; a plurality of context memories configured to store context parameters that are to be used by the entropy coding units; a common context memory for storing the context parameters that are to be used in common by at least two among the plurality of entropy coding units; and a memory control unit configured to write the context parameters to the context memories and the common context memory, wherein, at a first timing before a second entropy coding unit executes the processing for a left end block in a second block line subsequent to a first block line, in response to execution of the processing for a block in the first block line by a first entropy coding unit, the memory control unit writes context parameters based on the result of the entropy coding in the first entropy coding unit both to a first context memory which stores context parameters that are to be used by the first entropy coding unit, and to the common context memory; wherein, at a second timing after the first timing before the second entropy coding unit executes the processing for the left end block in the second block line, the memory control unit writes the context parameters based on the result of the entropy coding in the first entropy coding unit in the common context memory to a second context memory which stores context parameters that are to be used by the second entropy coding unit.