“…However, traditional methods [SDC09, PMC22, SMYA14, FTR18] are usually developed on the basis of user‐guided hints, so they are inappropriate for reference‐based colourization. As neural networks have been proven effective in object recognition and colour rendering [ZIE16, ZZI*17, XHZ*20], many deep learning models have been proposed to solve the sketch colourization problem by encoding text [HYES19, ZMG*19, CMG21], user‐guided hints [FHOO17, ZLW*18] and reference images [ZJLL17, LKL*20, SLWW19, AMT20] into colour information. Among the reference‐based methods, Akita et al.…”