Image encoding method, image decoding method, image encoding apparatus, image decoding apparatus, and image coding apparatus

An image decoder comprising:

• a processor;
• and
• a memory connected with the processor, wherein the processor, in operation, performs:
• generating a reference picture list by collecting candidate reference pictures, the reference picture list associating each of the candidate reference pictures with one of a plurality of indexes, the candidate reference pictures including (i) one or more first candidate reference pictures of a current view and (ii) one or more second candidate reference pictures of a reference view, the indexes being integers from zero to N−1, where N is a sum of a number of the first candidate reference pictures and a number of the second candidate reference pictures;
• determining whether a list modification flag read out from a bit stream is 0 or 1, the list modification flag being a 1-bit parameter;
• when the list modification flag is 0,
• identifying the candidate reference picture used for decoding based on an index selected from among the indexes;
• when the list modification flag is 1,
• reading out, from the bit stream, M replacement values provided for M modified indexes respectively, where M is a number of candidate reference pictures provided for decoding process, each of the replacement values being one of a plurality of integers from zero to N−1, and each of the modified indexes being associated with one of the candidate reference pictures having one of the indexes equal to the replacement value of each of the modified indexes;
• and
• identifying the candidate reference picture used for decoding based on a modified index selected from among the modified indexes.

An image decoding method comprising:

• generating a reference picture list by collecting candidate reference pictures, the reference picture list associating each of the candidate reference pictures with one of a plurality of indexes, the candidate reference pictures including (i) one or more first candidate reference pictures of a current view, (ii) one or more second candidate reference pictures of a reference view, and (iii) one or more third candidate reference pictures of a reference layer different from a current layer in scalable video coding (SVC), the indexes being integers from zero to N−1, where N is a sum of a number of the first candidate reference pictures, a number of the second candidate reference pictures, and a number of the third candidate reference pictures;
• determining whether a list modification flag read out from a bit stream is 0 or 1, the list modification flag being a 1-bit parameter;
• when the list modification flag is 0,
• identifying the candidate reference picture used for decoding based on an index selected from among the indexes;
• when the list modification flag is 1,
• reading out, from the bit stream, M replacement values provided for M modified indexes respectively, where M is a number of candidate reference pictures provided for decoding process, each of the replacement values being one of a plurality of integers from zero to N−1, and each of the modified indexes being associated with one of the candidate reference pictures having one of the indexes equal to the replacement value of each of the modified indexes;
• and
• identifying the candidate reference picture used for decoding based on a modified index selected from among the modified indexes.

An image decoder comprising:

• a processor;
• and
• a memory connected with the processor, wherein the processor, in operation, performs:
• generating a reference picture list by collecting candidate reference pictures, the reference picture list associating each of the candidate reference pictures with one of a plurality of indexes, the candidate reference pictures including (i) one or more first candidate reference pictures of a current view, (ii) one or more second candidate reference pictures of a reference view, and (iii) one or more third candidate reference pictures of a reference layer different from a current layer in scalable video coding (SVC), the indexes being integers from zero to N−1, where N is a sum of a number of the first candidate reference pictures, a number of the second candidate reference pictures, and a number of the third candidate reference pictures;
• determining whether a list modification flag read out from a bit stream is 0 or 1, the list modification flag being a 1-bit parameter;
• when the list modification flag is 0,
• identifying the candidate reference picture used for decoding based on an index selected from among the indexes;
• when the list modification flag is 1,
• reading out, from the bit stream, M replacement values provided for M modified indexes respectively, where M is a number of candidate reference pictures provided for decoding process, each of the replacement values being one of a plurality of integers from zero to N−1, and each of the modified indexes being associated with one of the candidate reference pictures having one of the indexes equal to the replacement value of each of the modified indexes;
• and
• identifying the candidate reference picture used for decoding based on a modified index selected from among the modified indexes.