Artistic Paper-cut Of Human Portrait And Its Psychological Evaluation

Portrait paper-cut is a traditional Chinese art form which conveys complex characteristics of human being with concise two-value logic. It is harder than other paper-cut subjects because human have acute visual perception on the structure of human face. It is also more challenging than other types of portrait art due to the special top-down mechanism we use when recognizing two-tone images. A satisfactory result often requires the highest level of skills of artists and consume them a considerable amount of time. Traditional thresholding methods rely highly on the qualities of images and bring about problems such as the missing of facial details and rough edges, which ruin the likeness and aesthetic quality of the figure. What's more, they lack the intrinsic patterns and hollows of traditional paper-cuts.In this paper, we propose an approach for rendering artistic paper-cut of human portrait based on And-Or Graph which compensates the deficiency of traditional thresholding methods. The framework is as follows:(1) Facial paper-cut based on And-Or Graph.Face plays the most important part in portrait likeness. We incorporate the prior knowledge artists employed in their creation into our rendering algorithm. In our approach, a bottom-up phase is first executed to extract information from the input photograph, and then a second top-down phase is used for adding artistic constrains to compensate the problems of traditional thresholding methods.(2) Post-processing for hair and clothes.Hair and clothes are essential parts of portrait paper-cuts. The artistic style of portrait paper-cut is well represented by the elegant and well-proportioned hollows of hair and clothes. For hair, we calculate the orientation field for the hair region, and employ sampling on the hair region according to the shading and orientation information. For clothes, the location, size and orientation of the hollows are derived from the shading and depth information of the clothes region. We further transform hollow patterns borrowed from traditional paper-cut according to the parameters we got and fill the clothes region with them. (3) Psychological experiments.In this part, we evaluate our portrait paper-cut algorithm from the perspective of human perception, and explore the key factors influencing the likeness of portrait paper-cut, which are significant for artistic rendering and future research.