State of the Art in Example-based Texture Synthesis

International audienceRecent years have witnessed significant progress in example-based texture synthesis algorithms. Given an example texture, these methods produce a larger texture that is tailored to the user's needs. In this state-of-the-art report, we aim to achieve three goals: (1) provide a tutorial that is easy to follow for readers who are not already familiar with the subject, (2) make a comprehensive survey and comparisons of different methods, and (3) sketch a vision for future work that can help motivate and guide readers that are interested in texture synthesis research. We cover fundamental algorithms as well as extensions and applications of texture synthesis

Synthesis, Editing, and Rendering of Multiscale Textures

The study of textures---images with repeated visual content---has produced a number of useful tools and algorithms for analysis, synthesis, editing, rendering, and a variety of other applications. However, the recent rapid growth in data storage and computational abilities has expanded the notion of what constitutes a texture. Modern textures can often outstrip traditional assumptions on input size by several orders of magnitude. Additionally, these multiscale textures typically contain features at not just one scale but rather across a wide range of scales, further violating existing assumptions. In order to meaningfully capture the large-scale features present in multiscale textures, we introduce a new example-based input representation, the exemplar graph. This representation enables allows us to efficiently define textures spanning a large--or possibly infinite--range of visual scales. We develop a hierarchical, parallelizable algorithm for performing texture synthesis from an input exemplar graph. In addition to automated generation, an increasingly important application of texture synthesis is in interactive tools for guiding texture design. This modality is especially important for multiscale textures, as they offer special perceptual challenges to artists. We examine algorithmic and engineering optimizations to enable real-time analysis and synthesis of multiscale textures, and explore potential implications for editing tools. Finally, we study the issue of display. To accurately view a large image at distance, some filtering operation must be performed. In many cases, such as traditional color images, the filtering operations are well-known. However, other texture representations, such as normal or displacement maps, present special difficulties for filtering. We treat the former case, presenting a principled analysis and algorithms for filtering and display of large normal maps

Synthesis, Editing, and Rendering of Multiscale Textures

The study of textures---images with repeated visual content---has produced a number of useful tools and algorithms for analysis, synthesis, editing, rendering, and a variety of other applications. However, the recent rapid growth in data storage and computational abilities has expanded the notion of what constitutes a texture. Modern textures can often outstrip traditional assumptions on input size by several orders of magnitude. Additionally, these multiscale textures typically contain features at not just one scale but rather across a wide range of scales, further violating existing assumptions. In order to meaningfully capture the large-scale features present in multiscale textures, we introduce a new example-based input representation, the exemplar graph. This representation enables allows us to efficiently define textures spanning a large--or possibly infinite--range of visual scales. We develop a hierarchical, parallelizable algorithm for performing texture synthesis from an input exemplar graph. In addition to automated generation, an increasingly important application of texture synthesis is in interactive tools for guiding texture design. This modality is especially important for multiscale textures, as they offer special perceptual challenges to artists. We examine algorithmic and engineering optimizations to enable real-time analysis and synthesis of multiscale textures, and explore potential implications for editing tools. Finally, we study the issue of display. To accurately view a large image at distance, some filtering operation must be performed. In many cases, such as traditional color images, the filtering operations are well-known. However, other texture representations, such as normal or displacement maps, present special difficulties for filtering. We treat the former case, presenting a principled analysis and algorithms for filtering and display of large normal maps

Strong Markov Random Field Model

The strong Markov random field (strong-MRF) model is a sub-model of the more general MRF-Gibbs model. The strong-MRF model defines a system who's field is Markovian with respect to a defined neighborhood and all sub-neighborhoods are also Markovian. A checkerboard pattern is a perfect example of a strong Markovian system. Although the strong Markovian system requires a more stringent assumption about the field, it does have some very nice mathematical properties. One mathematical property, is the ability to define the strong-MRF model with respect to its marginal distributions over the cliques. Also a direct equivalence to the Analysis-of-variance (ANOVA) log-linear construction can be proved. From this proof, the general ANOVA log-linear construction formula is acquired