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The construction of perceptual grouping displays using GERT
Maarten Demeyer1, Bart Machilsen
1Laboratory of Experimental Psychology, University of Leuven (K.U. Leuven), Tiensestraat 102, bus 3711, 3000, Leuven, Belgium. maarten.demeyer@psy.kuleuven.be
Abstract:
To study perceptual grouping processes, vision scientists often use stimuli consisting of spatially separated local elements that, together, elicit the percept of a global structure. We developed a set of methods for constructing such displays and implemented them in an open-source MATLAB toolbox, GERT (Grouping Elements Rendering Toolbox). The main purpose of GERT is to embed a contour in a field of randomly positioned elements, while avoiding the introduction of a local density cue. However, GERT's modular implementation enables the user to create a far greater variety of perceptual grouping displays, using these same methods. A generic rendering engine grants access to a variety of element-drawing functions, including Gabors, Gaussians, letters, and polygons.
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