An image encoding/decoding method and apparatus are provided. An image decoding method may comprise obtaining, from a bitstream, a feature set extracted from an input image using an artificial neural network-based feature extraction method, first information on importance of each of a plurality of channels included in the feature set and second information on a quantization method of the feature set, decoding the feature set, the first information and the second information, and dequantizing the decoded feature set based on the decoded first information and the decoded second information. The second information may comprise the number of quantization bits of each of the plurality of channels, and the number of quantization bits may be determined based on the importance of each of the plurality of channels.