According to the disclosure of the present document, a linear reshaper is used for LMCS and a single chroma residual scaling factor, which is directly signaled during chroma scaling of the LMCS, can be used. In addition, the number of flexible bins can be used for luma mapping so that the resource/cost (of software or hardware) required for an LMCS procedure is minimized, and the latency of coding is removed so that the LMCS procedure can be efficiently performed.