Bidirectional Texture Function Modeling: A State of the Art Survey

An ever-growing number of real-world computer vision applications require classification, segmentation, retrieval, or realistic rendering of genuine materials. However, the appearance of real materials dramatically changes with illumination and viewing variations. Thus, the only reliable representation of material visual properties requires capturing of its reflectance in as wide range of light and camera position combinations as possible. This is a principle of the recent most advanced texture representation, the Bidirectional Texture Function (BTF). Multispectral BTF is a seven-dimensional function that depends on view and illumination directions as well as on planar texture coordinates. BTF is typically obtained by measurement of thousands of images covering many combinations of illumination and viewing angles. However, the large size of such measurements has prohibited their practical exploitation in any sensible application until recently. During the last few years, the first BTF measurement, compression, modeling, and rendering methods have emerged. In this paper, we categorize, critically survey, and psychophysically compare such approaches, which were published in this newly arising and important computer vision and graphics area.

1 Introduction

Robust visual classification, segmentation, retrieval, or view/illumination invariant methods dealing with images of textured natural materials, as well as augmented reality applications creating virtual objects in rendered scenes with real material surface optical properties, require realistic physically correct textures. Such texture representation considerably depends on the view and illumination directions and can be efficiently and most accurately obtained in the form of rough surface textures represented by Bidirectional Texture Function. Additionally, applications of this advanced texture representation allow accurate photo-realistic material appearance approximation for such complex tasks as visual safety simulations or interior design in automotive/airspace industry (Fig. 2), architecture, or dermatology [8] among others.