An image coding method and apparatus and an image decoding method and apparatus are provided by the present document. The image coding method includes: implementing matching coding for pixels of an input video image to obtain one or more matching relationship parameters, herein the matching relationship parameters are parameters used in a process of constructing predicted values and/or reconstructed values of the pixels in the image; mapping the matching relationship parameters to obtain mapped values of the matching relationship parameters; and performing entropy coding on the mapped values of the matching relationship parameters. The present document addresses the problem existing in the conventional art which is caused by the direct implementation of entropy coding for matching relationship parameters and achieves a good data compression effect through entropy coding.