A closed-form solution to natural image matting

Interactive digital matting, the process of extracting a foreground object from an image based on limited user input, is an important task in image and video editing. From a computer vision perspective, this task is extremely challenging because it is massively ill-posed -- at each pixel we must estimate the foreground and the background colors, as well as the foreground opacity ("alpha matte") from a single color measurement. Current approaches either restrict the estimation to a small part of the image, estimating foreground and background colors based on nearby pixels where they are known, or perform iterative nonlinear estimation by alternating foreground and background color estimation with alpha estimation.In this paper we present a closed-form solution to natural image matting. We derive a cost function from local smoothness assumptions on foreground and background colors, and show that in the resulting expression it is possible to analytically eliminate the foreground and background colors to obtain a quadratic cost function in alpha. This allows us to find the globally optimal alpha matte by solving a sparse linear system of equations. Furthermore, the closed-form formula allows us to predict the properties of the solution by analyzing the eigenvectors of a sparse matrix, closely related to matrices used in spectral image segmentation algorithms. We show that high quality mattes for natural images may be obtained from a small amount of user input.     

Understanding team innovation: The role of team processes and structures.

The present study focused on innovation of teams, examining the contributions of team interaction processes (exchanging information, learning, motivating, and negotiating) and structures (functional heterogeneity and frequency of meetings) to innovation. Specifically, it was hypothesized that (a) team structures will be positively related to team innovation, (b) team heterogeneity will be positively related to team interaction processes, (c) team interaction processes will be positively related to team innovation, and (d) team interaction processes will mediate the relationship between team heterogeneity and team innovation. Results from a sample of 48 intact teams in elementary and secondary schools supported the main hypotheses. These results imply that the development of mutual interaction processes is a crucial mechanism for translating team heterogeneity into innovation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Strategies for coping with work-family conflict: The distinctive relationships of gender role ideology.

Study 1, with 266 employed parents, identified 8 coping strategies: super at home, good enough at home, delegation at home, priorities at home, super at work, good enough at work, delegation at work, and priorities at work. Study 2, with 679 employed parents, demonstrated a moderating effect of sex and gender role ideology in the relationship between coping strategy and work-family conflict. Specifically, the relationships between coping strategies (i.e., good enough at home, good enough at work, and delegation at work) and work interference with family were moderated by sex and gender role ideology. Regarding family interference with work, the relationships between coping strategies (i.e., good enough at home and good enough at work, delegation at home and delegation at work, and priorities at home) and family interference with work were moderated by sex and gender role ideology. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Orientation map for planning and design methods

This paper constructs a contextual space for plotting the positions of P and D (Planning and design) methods, thus offering a framework for analysing, comparing and contrasting P and D approaches. Three dimensions make up this space: strategy, people involvement and attitude toward change. The strategy continuum varies between the extreme ends: pure inquiry and pure will. The people involvement dimension describes the passage of design control from designer to client. The scale for change attitude spans the distance between aversion to change and exploitation of change. Several well-known P and D methods and approaches are discussed and plotted, to test the validity of the suggested framework.     

Aspects of endowment: A query theory of value construction.

How do people judge the monetary value of objects? One clue is provided by the typical endowment study (D. Kahneman, J. L. Knetsch, & R. H. Thaler, 1991), in which participants are randomly given either a good, such as a coffee mug, that they may later sell ("sellers") or a choice between the good and amounts of cash ("choosers"). Sellers typically demand at least twice as much as choosers, inconsistent with economic theory. This result is usually explained by an increased weighting of losses, or loss aversion. The authors provide a memory-based account of endowment, suggesting that people construct values by posing a series of queries whose order differs for sellers and choosers. Because of output interference, these queries retrieve different aspects of the object and the medium of exchange, producing different valuations. The authors show that the content and structure of the recalled aspects differ for selling and choosing and that these aspects predict valuations. Merely altering the order in which queries are posed can eliminate the endowment effect, and changing the order of queries can produce endowment-like effects without ownership. (PsycINFO Database Record (c) 2010 APA, all rights reserved)