the chromatic number of a graph g, denoted by χ(g), is the minimum number of colors such that g can be colored with these colors in such a way that no two adjacent vertices have the same color. a clique in a graph is a set of mutually adjacent vertices. the maximum size of a clique in a graph g is called the clique number of g. the turán graph tn(k) is a complete k-partite graph whose partition...

A memory color is an observer’s knowledge of a typical object color. The typicality of the memorized color implies that the observer considers the memory color to be representative or “canonical” for the range of colors, in which the respective object occurs. In this way, it determines the observer’s expectation about an object’s color based on her or his prior knowledge. For example, an observ...

determination of boundary surface structures is commonly used for data interpretation. horizontal and vertical derivatives are useful tool for determining the edges boundary. using horizontal and vertical derivative in signal analysis method; that is effective method for interpretation of edges boundary, have been used commercially.in acquisition potential field data, using different methods of...

When an observer with a holistic viewing attitude perceives transparency in an achromatic two-dimensional pattern, some areas of the pattern form a single transparent phenomenal surface. In each of these areas the observer simultaneously perceives the gray color of the transparent surface and the gray color of the background that is visible through the transparent surface. With an analytic view...

Color processing imposes a new constraint on stereo vision algorithms: The assumption of constant color on object surfaces used to align local correlation windows with object boundaries has improved the accuracy of recent window based stereo algorithms significantly. While several algorithms have been presented that work with adaptive correlation windows defined by color similarity, only a few ...

This contribution proposes a fuzzy approach to color image filtering by the fuzzy modeling of the concept of color credibility. Based on the perceptual notion of color resemblance, the colors are modeled as fuzzy sets in the color space. The filtering principle is to select at the filters output the color that is the most credible with respect to the rest of colors within the filtering window. ...

The purpose of this research is to analyze the lowlevel features of images as a representation of semantic concept. This paper proposes a flexible approach for clustering features of images and mapping the low-level image features to the highlevel concept recognition. Owing to the uncertainty of image features for human’s recognition, we use the approach of fuzzy colors clustering to analyze im...

Two groups of freshman students, enrolled in their first writing course in EFL, participated in the study. Before instruction, no significant differences were found between both groups in their writing ability. Both groups were exposed to the same in-class writing instruction. Since students have difficulty generating ideas in EFL, writing paragraphs with topic sentences and supporting details,...

Four color theorem, using concept of free-planar graphs, is discussed.