Decoding device, encoding device, decoding method, and encoding method

Abstract

A decoding device (200) comprises a memory (b2) and a circuit (b1) connected to the memory (b2). In operation, the circuit (b1) decodes, from a bitstream, information for determining, for each of a plurality of regions in a picture, a control parameter set of neural network filter processing applied to the picture (S401), decodes the picture from the bitstream (S402), and applies the neural network filter processing to the picture (S403). In the neural network filter processing, a single neural network filter is used with respect to the picture, and the control parameter set determined on the basis of the information is used with respect to each of the plurality of regions.