Image encoding and decoding method supporting plurality of layers and apparatus using same
An image decoding method supporting a plurality of layers according to the present invention may comprise the steps of: generating an inter-layer reference picture set with respect to one or more reference layers to which a current picture can refer; generating an initial reference picture list including the inter-layer reference picture set; and predicting the current picture on the basis of the initial reference picture list. Accordingly, the present invention provides a method for generating a reference picture list including a picture of a layer, which is different from a layer to be currently encoded and decoded, and an apparatus using the same.
1. A method for decoding a video supporting multiple layers with a decoding apparatus, comprising:
generating, with the decoding apparatus, an inter-layer reference picture set by using a picture in at least one reference layer capable of being referred to by a current picture;
generating, with the decoding apparatus, an initial reference picture list including the inter-layer reference picture set and a temporal reference picture set; and
performing, with the decoding apparatus, prediction of the current picture based on the initial reference picture list,
wherein the generating the inter-layer reference picture set comprises:
determining, with the decoding apparatus, among a plurality of temporal sub-layers included in the reference layer, a maximum index of temporal sub-layer used for the inter layer prediction; and
generating the inter-layer reference picture set based on the determined maximum index of temporal sub-layer,
wherein the temporal reference picture set comprises at least one of a short-term reference picture set or a long-term reference picture set, and
wherein the inter-layer reference picture set comprises a first sub-reference layer picture set and a second sub-reference layer picture set,
wherein the first sub-reference layer picture set is arranged, in the reference picture list, between a first short-term reference picture set including short-term reference pictures having POCs less than POCs of the current picture and a second short-term reference picture set including short-term reference pictures having POCs greater than POCs of the current picture and
the second sub-reference layer picture set is arranged, in the reference picture list, at the end of a long-term reference picture set including long-term reference pictures,
wherein the temporal reference picture set and the inter-layer reference picture set belong to different layers.
2. The method of claim 1 , wherein the generating the inter-layer reference picture set is performed based on an index (tempralId) of a temporal sub-layer to which the current picture belongs.
3. The method of claim 2 , wherein, as the index (tempralId) of the temporal sub-layer to which the current picture belongs is smaller, the inter-layer reference picture set is aligned at a lower sequential position of the initial reference picture list.
4. The method of claim 2 , wherein, as a difference between values of the index (tempralId) of the temporal sub-layer to which the current picture belongs and an index (tempralId) of a temporal sub-layer of the reference layer is smaller, the inter-layer reference picture set is aligned at a lower sequential position of the initial reference picture list.
5. The method of claim 1 , wherein, when a value of an index (tempralId) of a temporal sub-layer to which the picture in the reference layer belongs is greater than the maximum index of temporal sub-layer, the picture in the reference layer is not included in the inter-layer reference picture set.