We propose a non-photorealistic rendering method for automatically generating point-light-style (PLS) images from photographic images using peripheral difference filters with different window sizes. The proposed method can express PLS patterns near the edges of photographic images as dots. To verify the effectiveness of the proposed method, experiments were conducted to visually confirm PLS images generated from various photographic images.

We propose a non-photorealistic rendering method to automatically generate reaction-diffusion-pattern-like images from photographic images. The proposed method uses smoothing filter with a circular window, and changes the size of the circular window depending on the position in photographic images. By partially changing the size of the circular window, the size of reaction-diffusion patterns can be changed partially. To verify the effectiveness of the proposed method, experiments were conducted to apply the proposed method to various photographic images.

We propose a non-photorealistic rendering method for generating edge-preserving bubble images from gray-scale photographic images. Bubble images are non-photorealistic images embedded in many bubbles, and edge-preserving bubble images are bubble images where edges in photographic images are preserved. The proposed method is executed by an iterative processing using absolute difference in window. The proposed method has features that processing is simple and fast. To validate the effectiveness of the proposed method, experiments using various photographic images are conducted. Results show that the proposed method can generate edge-preserving bubble images by preserving the edges of photographic images and the processing speed is high.

A non-photorealistic rendering method has been proposed for generating oil-film-like images from photographic images by bilateral infra-envelope filter. The conventional method has a disadvantage that it takes much time to process. We propose a method for generating oil-film-like images that can be processed faster than the conventional method. The proposed method uses an iterative process with upper and lower smoothing filters. To verify the effectiveness of the proposed method, we conduct experiments using Lenna image. As a result of the experiments, we show that the proposed method can process faster than the conventional method.

We propose a system named ETIS (Energy-based Tree Illustration System) for automatically generating tree illustrations characteristic of two-dimensional ones with features such as exaggerated branch curves, leaves, and flowers. The growth behavior of the trees can be controlled by adjusting the energy. The canopy shape and the region to fill with leaves and flowers are also controlled by hand-drawn guide lines.

A non-photorealistic rendering method creates oil-film-like images, expressed with colorful, smooth curves similar to the oil films generated on the surface of glass or water, from color photo images. The proposed method generates oil-film-like images through iterative processing between a bilateral infra-envelope filter and an unsharp mask. In order to verify the effectiveness of the proposed method, tests using a Lena image were performed, and visual assessment of oil-film-like images was conducted for changes in appearance as the parameter values of the proposed method were varied. As a result of tests, the optimal value of parameters was found for generating oil-film patterns.

We propose a non-photorealistic rendering method for generating moire-picture-like color images from color photographs. The proposed method is performed in two steps. First, images with a staircasing effect are generated by a bilateral filter. Second, moire patterns are generated with an improved bilateral filter called an anti-bilateral filter. The characteristic of the anti-bilateral filter is to emphasize gradual boundaries.

A non-photorealistic rendering technique is presented for generating images such as stippling images and paper mosaic images with various shapes of paper pieces. Paper pieces are spatially arranged by using an anisotropic Lp poisson disk sampling. The shape of paper pieces is adaptively varied by changing the value of p. We demonstrate with experiments that edges and details in an input image are preserved by the pieces according to the anisotropy of their shape.

We propose a method for halftoning grayscale images by drawing weighted centroidal Voronoi tessellations (WCVTs) with black lines on white image planes. Based on the fact that CVT approaches a uniform hexagonal lattice asymptotically, we derive a relationship of darkness between input grayscale images and the corresponding halftone images. Then the derived relationship is used for adjusting the contrast of the halftone images. Experimental results show that the generated halftone images can reproduce the original tone in the input images faithfully.

Main bottleneck of photomosaic algorithm is a search for a best matched image. Unlike several techniques which use fast approximation search for increasing the speed, we propose a parallel framework for fast photomosaic using a programmable GPU. This paper suggests a design of vertex structure for a best match searching on each cell of photomosaic grid and shows a texture representation of image database. The shader programs which are used for searching a best match and rendering image tiles into a display are presented. In addition, a simple duplicate reduction and color correction methods are proposed. Our algorithm not only offers dramatic enhancement of speed, but also always guarantees the 'exact' result.

Landscapes have been the main theme in Chinese painting for over one thousand years. Chinese ink painting is a form of non-photorealistic rendering. Terrain is the major subject in Chinese landscape painting, and surface wrinkles are important in conveying the orientation of mountains and contributing to the atmosphere. Over the centuries, masters of Chinese landscape painting have developed various kinds of wrinkles. This work develops a set of novel methods for rendering wrinkles in Chinese landscape painting. A three-dimensional terrain is drawn as an outline and wrinkles, using information on the shape, shade and orientation of the terrain's polygonal surface. The major contribution of this work lies in the modeling and implementation of six major types of wrinkles on the surface of terrain, using traditional Chinese brush techniques. Users can select a style of wrinkle and input parameters to control the desired effect. The proposed method then completes the painting process automatically.

This paper presents a new algorithm for efficiently detecting silhouette voxels in volume objects. The high performance of the algorithm is partly due to its ability to exclude all the gradient vectors not associated with silhouettes from further consideration. A judicious re-arrangement of the voxels enhances its efficiency. We have studied its performance through computer simulations. The results indicate a manifold improvement over conventional algorithms. A parallel version of the algorithm has also been described in the paper. Its performance is quite understandably impressive.