Visibility Constraints in Depiction: Objects Experienced versus Objects Depicted

Appearance Transformation of 3d Objects Depicted in Images

In this work we propose a method that facilitates transport of a material appearance between objects depicted in two different images. The approach consists of two steps performed on both the material and original images, capturing the object material, and the object of interest itself. The diffuse and specular reflection components are separated by removing specular highlights from the materia...

Category of Polygroup Objects

Computing the Visibility Map of Fat Objects

We give an output-sensitive algorithm for computing the visibility map of a set of n constant-complexity convex fat polyhedra or curved objects in 3-space. Our algorithm runs in O((n + k) polylog n) time, where k is the combinatorial complexity of the visibility map. This is the first algorithm for computing the visibility map of fat objects that does not require a depth order on the objects an...

Gorenstein projective objects in Abelian categories

Let $mathcal {A}$ be an abelian category with enough projective objects and $mathcal {X}$ be a full subcategory of $mathcal {A}$. We define Gorenstein projective objects with respect to $mathcal {X}$ and $mathcal{Y}_{mathcal{X}}$, respectively, where $mathcal{Y}_{mathcal{X}}$=${ Yin Ch(mathcal {A})| Y$ is acyclic and $Z_{n}Yinmathcal{X}}$. We point out that under certain hypotheses, these two G...

Development of graphic formulas for the depiction of familiar objects

We investigated the nature of graphic formulas in 5-, 7-, and 9-year-old children when they were asked to draw a house and a television in a free condition, and then to draw from photographs of these objects. Assuming that the frequency of occurrence of a feature in children’s drawings reflects its semantic weight, we studied the relations between occurrence and order of production of features ...