Encoding device, decoding device, encoding method, and decoding method for efficient coding

摘要

According to an embodiment, an encoding device includes a deriving unit and an encoding unit. The deriving unit derives a first reference value based on fixed point precision representing roughness of a weighting factor that is used for multiplying a reference image. The encoding unit encodes a first difference value and the fixed point precision. The first difference value is a difference value between the weighting factor and the first reference. The weighting factor is included in a first range of given bit precision having the first reference value at approximate center. The first difference value is in the given range.

主权项

1. An encoding device comprising:
processing circuitry configured to determine a first reference value based on fixed point precision representing precision of a weighting factor that is used for multiplying a reference image; encode a first difference value and the fixed point precision, the first difference value being a difference value between the weighting factor and the first reference value; determine a second reference value of an offset of a color difference to be added to the reference image for correcting pixel value, by subtracting a value obtained by both multiplying a median value of a maximum pixel value by the weighting factor and shifting to the right for a bit or bits of the fixed point precision, from the median value; and encode a second difference value that is a difference value between the offset and the second reference value, wherein the first difference value is included in a first range of given bit precision, the first range having 0 at an approximate center, and the second difference value is included in a second range of given bit precision, the second range having a given value as approximate center.