Image encoding/decoding method and device

An apparatus for image decoding that supports a plurality of layers, the apparatus comprising:

• one or more processors configured to:
• decode a picture of a first layer which a picture of a second layer including a current decoding target block refers to;
• map the picture of the first layer to a picture size of the second layer;
• configure a first reference picture list for the picture of the second layer by adding the mapped picture of the first layer to a first predetermined position in the first reference picture list;
• configure a second reference picture list for the picture of the second layer by adding the mapped picture of the first layer to a second predetermined position in the second reference picture list;
• generate prediction samples of the current decoding target block by predicting the current decoding target block of the second layer based on the first reference picture list and the second reference picture list to generate a prediction block;
• generate a residual block of the current decoding target block;
• and
• reconstruct the current decoding target block based on the prediction block and the residual block,
• wherein the first predetermined position is different from the second predetermined position, which is an end position in the second reference picture list.

A method for image encoding that supports a plurality of layers, the method being performed by an encoding apparatus and comprising:

• decoding a picture of a first layer which a picture of a second layer including a current encoding target block refers to;
• mapping the picture of the first layer to a picture size of the second layer;
• configuring a first reference picture list for the picture of the second layer by adding the mapped picture of the first layer to a first predetermined position in the first reference picture list;
• configuring a second reference picture list for the picture of the second layer by adding the mapped picture of the first layer to a second predetermined position in the second reference picture list;
• generating prediction samples of the current encoding target block by predicting the current encoding target block of the second layer based on the mapped picture of the first layer to generate a prediction block;
• generating a residual block of the current encoding target block based on the prediction block;
• and
• encoding the residual block,
• wherein the first predetermined position is different from the second predetermined position, which is an end position in the second reference picture list.

An apparatus for image encoding that supports a plurality of layers, the apparatus comprising:

• one or more processors configured to:
• decode a picture of a first layer which a picture of a second layer including a current encoding target block refers to;
• map the picture of the first layer to a picture size of the second layer;
• configure a first reference picture list for the picture of the second layer by adding the mapped picture of the first layer to a first predetermined position in the first reference picture list;
• configure a second reference picture list for the picture of the second layer by adding the mapped picture of the first layer to a second predetermined position in the second reference picture list;
• and
• generate prediction samples of the current encoding target block by predicting the current encoding target block of the second layer based on the mapped picture of the first layer to generate a prediction block;
• generate a residual block of the current encoding target block based on the prediction block;
• and
• encode the residual block,
• wherein the first predetermined position is different from the second predetermined position, which is an end position in the second reference picture list.

A non-transitory computer-readable medium storing a bitstream generated by a method for image encoding that supports a plurality of layers, the method being performed by an encoding apparatus and comprising:

• decoding a picture of a first layer which a picture of a second layer including a current encoding target block refers to;
• mapping the picture of the first layer to a picture size of the second layer;
• configuring a first reference picture list for the picture of the second layer by adding the mapped picture of the first layer to a first predetermined position in the first reference picture list;
• configuring a second reference picture list for the picture of the second layer by adding the mapped picture of the first layer to a second predetermined position in the second reference picture list;
• and
• generating prediction samples of the current encoding target block by predicting the current encoding target block of the second layer based on the mapped picture of the first layer to generate a prediction block;
• generating a residual block of the current encoding target block based on the prediction block;
• and
• encoding the residual block,
• wherein the first predetermined position is different from the second predetermined position, which is an end position in the second reference picture list.