Integrated tone and structure refinement for high-fidelity colour transfer

A high-fidelity colour transfer should align the colour distributions between images and meanwhile avoid the damage to the original structure. However, the traditional methods often fail to yield high-fidelity transfer results due to some existing tone and structure artefacts. In this study, the authors propose a new framework to effectively integrate the tone and structure refinements of colour transfer. They develop the ideas of image decomposition and gradient guidance to perform tone reconstruction while protecting original structure. Its overall flow includes the five key steps: tone clustering, structure extraction, structure optimisation, gradient-guided tone reconstruction, and structure restoration. Moreover, they propose an evaluation metric to measure the differences of tone and structure between images. They demonstrate the performance of the proposed method through a number of experiments in visual comparison and objective evaluation.