Non-Photorealistic Rendering

Cílem této diplomové práce je prozkoumat možnosti nefotorealistického zobrazování, zaměřit se na oblast transformace obrazu a následně navrhnout algoritmus pro zpracování videa na jeho "cartoon" reprezentaci. Práce popisuje analýzu problému, návrh algoritmu a jeho implementaci.The purpose of this diploma thesis is to analyze possibilities of non-photorealistic rendering focused on area of image transformation and afterwards design algorithm for video postprocessing to it's cartoon representation. The thesis describes problem analysis, design of the algorithm and it's implementation.

Non-Photorealistic Rendering

Ústředním cílem této práce je kromě úvodu do problematiky nefotorealistického zobrazování, poskytnutí návrhu a možného řešení realizace systému, který toto zobrazování umožňuje ve formě obrazového post-processingu. Popisuje řešení dostatečně flexibilní na to, aby umožňovalo uživateli kromě již vestavěných filtrů, tvořit filtry vlastní a rekurzivně je využívat při tvorbě dalších, nových filtrů, pro tento typ zobrazování. Její součástí je tak i jakýsi manuál, který popisuje základní syntaxi a možnosti tohoto systému.The main purpose of this thesis besides providing the reader with basics of non-photorealistic rendering, is concept and possible solution for system realization, which is capable of this rendering using image post-processing. This thesis describes solution that is sufficiently flexible to support use of integrated filters along with the creation of new ones that can be recursively used to create another filters for this type of rendering. Thus part of this thesis is some kind of manual which provide basic syntax description and possibilities of use.

CLD-shaped Brushstrokes in Non-Photorealistic Rendering

Rendering techniques based on a random grid can be improved by adapting brushstrokes to the shape of different areas of the original picture. In this paper, the concept of Coherence Length Diagram is applied to determine the adaptive brushstrokes, in order to simulate an impressionist painting. Some examples are provided to instance the proposed algorithm.Comment: Keywords: Image processing, Non-photorealistic processing, Image-based rendering Coherence Length Diagra

Non-photorealistic image rendering with a labyrinthine tiling

The paper describes a new image processing for a non-photorealistic rendering. The algorithm is based on a random generation of gray tones and competing statistical requirements. The gray tone value of each pixel in the starting image is replaced selecting among randomly generated tone values, according to the statistics of nearest-neighbor and next-nearest-neighbor pixels. Two competing conditions for replacing the tone values - one position on the local mean value the other on the local variance - produce a peculiar pattern on the image. This pattern has a labyrinthine tiling aspect. For certain subjects, the pattern enhances the look of the image.Comment: 9 pages, 5 figure

Image Sampling with Quasicrystals

We investigate the use of quasicrystals in image sampling. Quasicrystals produce space-filling, non-periodic point sets that are uniformly discrete and relatively dense, thereby ensuring the sample sites are evenly spread out throughout the sampled image. Their self-similar structure can be attractive for creating sampling patterns endowed with a decorative symmetry. We present a brief general overview of the algebraic theory of cut-and-project quasicrystals based on the geometry of the golden ratio. To assess the practical utility of quasicrystal sampling, we evaluate the visual effects of a variety of non-adaptive image sampling strategies on photorealistic image reconstruction and non-photorealistic image rendering used in multiresolution image representations. For computer visualization of point sets used in image sampling, we introduce a mosaic rendering technique.Comment: For a full resolution version of this paper, along with supplementary materials, please visit at http://www.Eyemaginary.com/Portfolio/Publications.htm

Interactive non-photorealistic rendering

Due to increasing demands of artistic style with Interactive Rate, we propose this review paper as a starting point for any person interested in researching of interactive non-photorealistic rendering. As a simple yet effective means of visual communication, interactive non-photorealistic rendering generates images that are closer to human-drawn than are created by traditional computer graphics techniques with more expressing meaningful visual information. This paper presents taxonomy of interactive non-photorealistic rendering techniques which developed over the past two decades, structured according to the design characteristics and behavior of each technique. Also, it covers the most important algorithms in interactive stylized shade and line drawing, and separately discussing their advantages and disadvantages. The review then concludes with a discussion of the main issues and technical challenges for Interactive Non-Photorealistic Rendering techniques. In addition, this paper discusses the effect of modified phong shading model in order to create toon shading appearance

Non-Photorealistic Rendering of Algorithmically Generated Trees

This work presents a novel rendering technique inspired by artistic approaches. Instead of trying to recreate the appearance of a traditional medium, such as charcoal or watercolor, this approach is a mixture of both photo-realism and abstraction. Artists use a process of abstraction to provide structural information about subjects that do not have clearly defined shapes, such as groups of leaves in a tree. For example, an artist will first use a color wash to approximate a group of leaves, then add detail on top of parts of this wash to indicate individual leaves. Similarly, we use an abstract shape that approximates the image of leaves clustered at the end of a branch. To prevent oversimplification, we add photo-realistic detail using a blending process. Inter-frame coherence is achieved by smoothly interpolating the abstract shapes as well as by the continuity inherent in the photo-realistically rendered detail