Research for creating impressive images like paintings has attained more and more importance because of the recent growth in processing images. Among many painting styles, watercolor style gives a strong impression because of its thin colors and its soft appearance. This paper proposes a method to create watercolor style images from input images, for instance photographs. In contrast with the previously proposed watercolor methods that focuses only on simulating the effects of watercolor medium such as the mottled appearance and the color glazing, the proposed method also considers how the watercolor paintings are painted in order to simulate artists′ painting techniques. In the proposed method, artists′ painting techniques are represented using painting rules. Several painting rules are provided, in addition, user can specify their own painting rules. These painting rules are used for generating strokes to paint the objects. Painting techniques are simulated by first detecting the objects in the input image and generating strokes for each object according to the painting rules. The properties of watercolor medium are simulated by approximating each stroke with sampling points and diffuses their color to nearby pixels. Using the proposed method, a user can interactively create watercolor style images.

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Materials exposed to the elements change in appearance because of aging. Because wood is an organic substance, cracks and the surface erosion occur easily. To produce realistic computer graphic images, we need simulate the aging phenomenon also. Here, we propose a visual simulation of the distortion, cracking, and erosion of wood. In this method, wood is represented by a tetrahedral mesh. By setting semi-physical variables at each vertex in this mesh, a visual simulation of wood aging can be accomplished. The surface of the wood is defined by values assigned to the superficial tetrahedral mesh vertices. Changes in the surface are achieved by value changes. The effectiveness of this method is demonstrated by applications on a plank and shapes such as a bunny and an armadillo statue.

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Non-photorealistic rendering has become an important research topics in computer graphics in recent years. We have previously proposed a non-photorealistic rendering method to generate Suibokuga-like images of trees. This method was suitable only for representing trees in Mokkotsuho paintings because the images were generated from three-dimensional skeleton data. In this paper, we propose a method to generate Suibokuga-like images of arbitrary objects from three-dimensional geometric models, such as polygonal models. The proposed method realizes Kou, Ten, and Shun brush stroke techniques for creating Sensenbyoho paintings, which are a typical Suibokuga style for representing landscapes. Moreover, the images can be generated from arbitrary viewpoints and light source information. The ability of this method is demonstrated by showing various example.

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In the painterly rendering, the direction of the brush stroke is a very important factor. We propose a technique for automatic generation of ideal stroke direction reflecting the feature of the object. Our technique generates the stroke direction using 3D thinning of the object. As this technique specifies the direction on the 3D surface, it is suitable for animation. We also implemented suiboku-ga-style rendering using our technique. We specifies the starting points of strokes on the 3D surface in addition to the stroke direction. By doing so, our rendering algorithm can generate not only a still picture but also the animation with little flickering in suiboku-ga style. We believe that our stroke direction specification algorithm can also be applied to other NPRs such as pencil sketch drawing.

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On the theme of expressing the cosmos on the palm, this work made the interactive work using 3D computer graphics projected on the fog display and the acceleration sensor for input device.

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Visualization of graph data is an active research topic. Several studies of graph data visualization applied dynamics models, molecular models to nodes, and spring models to arcs, to properly place nodes of the graph onto display spaces. This paper proposes an improved force-directed graph data visualization method, and its extension to visualization of hierarchical graph data. The method places nodes of the graph one-by-one, so that it reduces the computation time and improves the display layout. The paper also proposes an application of the method to visualization of Web sites. It maps Web pages as nodes, hyper links as arcs, and directory as hierarchy, to form a hierarchcal graph data. It represents the overview of Web sites by visualizing the hierarchical graph data by above method.

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