Visual wetness perception based on image color statistics

Color vision provides humans and animals with the abilities to discriminate colors based on the wavelength composition of light and to determine the location and identity of objects of interest in cluttered scenes (e.g., ripe fruit among foliage). However, we argue that color vision can inform us about much more than color alone. Since a trichromatic image carries more information about the optical properties of a scene than a monochromatic image does, color can help us recognize complex material qualities. Here we show that human vision uses color statistics of an image for the perception of an ecologically important surface condition (i.e., wetness). Psychophysical experiments showed that overall enhancement of chromatic saturation, combined with a luminance tone change that increases the darkness and glossiness of the image, tended to make dry scenes look wetter. Theoretical analysis along with image analysis of real objects indicated that our image transformation, which we call the wetness enhancing transformation, is consistent with actual optical changes produced by surface wetting. Furthermore, we found that the wetness enhancing transformation operator was more effective for the images with many colors (large hue entropy) than for those with few colors (small hue entropy). The hue entropy may be used to separate surface wetness from other surface states having similar optical properties. While surface wetness and surface color might seem to be independent, there are higher order color statistics that can influence wetness judgments, in accord with the ecological statistics. The present findings indicate that the visual system uses color image statistics in an elegant way to help estimate the complex physical status of a scene

Kinetics of wetting and spreading of droplets over various substrates

There has been a substantial increase in the number of publications in the field of wetting and spreading since 2010. This increase in the rate of publications can be attributed to the broader application of wetting phenomena in new areas. It is impossible to review such a huge number of publications; that is, some topics in the field of wetting and spreading are selected to be discussed below. These topics are as follows: (i) Contact angle hysteresis on smooth homogeneous solid surfaces via disjoining/conjoining pressure. It is shown that the hysteresis contact angles can be calculated via disjoining/conjoining pressure. The theory indicates that the equilibrium contact angle is closer to a static receding contact angle than to a static advancing contact angle. (ii) The wetting of deformable substrates, which is caused by surface forces action in the vicinity of the apparent three-phase contact line, leading to a deformation on the substrate. (iii) The kinetics of wetting and spreading of non-Newtonian liquid (blood) over porous substrates. We showed that in spite of the enormous complexity of blood, the spreading over porous substrate can be described using a relatively simple model: a power low-shear-thinning non-Newtonian liquid. (iv) The kinetics of spreading of surfactant solutions. In this part, new results related to various surfactant solution mixtures (synergy and crystallization) are discussed, which shows some possible direction for the future revealing of superspreading phenomena. (v) The kinetics of spreading of surfactant solutions over hair. Fundamental problems to be solved are identified

Interactive Virtual Hair Salon

Abstract User interaction with animated hair is desirable for various applications but difficult because it requires real-time animation and rendering of hair. Hair modeling, in cluding styling, simulation, and rendering, is computationally challenging due to the enormous number of deformable hair strands on a human head, elevating the computational complexity of many essential steps, such as collision detection and self-shadowing for hair. Using simulation localization techniques, multi-resolution representations, and graphics hardware rendering acceleration, we have developed a physically-based virtual hair salon system that simulates and renders hair at accelerated rates, enabling users to interactively style virtual hair. With a 3D haptic interface, users can directly manipulate and position hair strands, as well as employ real-world styling applications (cutting, blow-drying, etc.) to create hairstyles more intuitively than previous techniques

Analyse und Vergleich der Maya-Plugins XGen und Yeti für die Erstellung und Simulation von Haaren

In der vorliegenden Bachelorarbeit werden die beiden Maya-Plugins XGen und Yeti auf die Erzeugung von Haaren hin analysiert und anschließend miteinander verglichen. Zunächst wird eine breite Basis an Wissen zu Haaren allgemein geschaffen und erörtert, wie diese Informationen helfen maximal möglichst realistische Haare in einem 3D Programm zu kreieren, sowie welche Besonderheiten bei computergenerierten Haaren zu beachten sind. Daraufhin werden die Grundlagen der beiden Plugins in den Bereichen Grooming, Shading und Simulation erläutert und auf grundsätzliche Workflows bei der Erstellung von Haaren in XGen und Yeti eingegangen. Zuletzt werden die beiden Programme, mit besonderem Augenmerk auf die Benutzung durch Einsteiger, in den zuvor beschriebenen Punkten miteinander verglichen.In the following thesis the two Maya-Plugins XGen and Yeti will be analysed and compared regarding the creation of hair. First of all, a broad basis of knowledge of hair over all will be set and it will be discussed how this infomation help creating hair as realisticly as possible, as well as what particularities in computergenerated hair have to be taken account of. Furthermore the fundamentals of both plugins in the fields of grooming, shading and simulation will be discussed and the essential workflows of the creation of hair in XGen and Yeti put forth. Lastly, both programs will be compared regarding the previous listed aspects with special focus on the usage through beginners