According to the disclosure of the present document, for LMCS, a linear reshaper may be used, LMCS codewords (or ranges thereof) may be restricted, and in the chroma scaling of the LMCS, a single chroma residual scaling factor may be used. Accordingly, the resources/cost (of software or hardware) necessary for an LMCS procedure may be minimized, and latency in coding may be eliminated, thus enabling the LMCS procedure to be efficiently performed.