Visual Memory Exp. Demo by R Sekuler

Visual memory --testing your ability to recognize things you've just seen.

Demos with gratings
Demos with synthetic faces

References
Robert Sekuler
http://people.brandeis.edu/~sekuler/

From Fragments to Objects

From Fragments to Objects : Segmentation and Grouping in Vision (Advances in Psychology (Amsterdam, Netherlands), 130,)-US-
ISBN:0444505067 (Hard cover book)
Shipley, Thomas F. (EDT) /Kellman, Philip J. (EDT) /Publisher:North-Holland Published 2001/12

Contents List
Philosophy and History of Perceptual Unit Formation"object" in perception and cognition, R. Schwartz; Balls of wax and cans of worms - the early history of object perception, M. Atherton; Development: Perceptual unit formation in infancy, M.E. Arterberry; Perceptual units and their mapping with language, B. Landau. Attention: An object substitution theory of visual masking, J.T. Enns, V. Di Lollo; Attention and unit formation - a biased competition account of object-based attention, S.P. Vecera, M. Behrmann. Models of Segmentation and Grouping: Geometric and neural models of object perception, P.J. Kellman et al; Varieties of grouping and its role in determining surface layout, B. Gillam; Amodal completion - a case study in grouping, A.B. Sekuler, R.F. Murray; Perceptual organization as generic object recognition, D.W. Jacobs; Simplicity, regularity, and perceptual interpretations - a structural information approach, R. Van Lier; Computational neural models of spatial integration in perceptual grouping, H. Neumann, E. Mingolla; Part-based representations of visual shape and implications for visual cognition, M. Singh, D.D. Hoffman. Spatiotemporal Segmentation and Grouping: Gaze control for face learning and recognition by humans and machines, J. Henderson et al; The visual interpretation of object and human movement, M. Shiffrar; Contours from apparent motion - a computational theory, W. Prophet et al; Breathing illusions and boundary formation in space-time, N. Bruno; Perception of occluding and occluded objects over time - spatiotemporal segmentation and unit formation, T.F. Shipley, D.W. Cunningham.

Murray, Gold, Bennett, Sekuler (2001)

ECVP 2001 abstract

Perceptually interpolated contours in shape discrimination
R F Murray, J M Gold, P J Bennett, A B Sekuler (Department of Psychology, University of Toronto, 100 St George Street, Toronto, Ontario M5S 3G3, Canada)

Observers use perceptually interpolated contours to perform some shape discrimination tasks, eg illusory and occluded contours to discriminate between Kanizsa squares (Murray et al, 2000 Perception 29 Supplement, 122). Do observers use contours defined only by perceptual grouping? We measured classification images in a task where observers discriminated between patterns made of four inward-facing Ls arranged as the corners of a square. The Ls were perceptually grouped as a square, but produced no illusory contours. Observers did not use whole sides of these grouping-defined squares. Rather, they mainly used the Ls, and were only slightly influenced by the empty regions between the Ls. This is in marked contrast to Murray et al's results with Kanizsa squares. Do observers use illusory contours that do not bound a region of illusory brightness? We measured classification images in a task where observers discriminated between Kanizsa squares defined by two white and two black inducers. These stimuli produced illusory contours, but the illusory square had the same brightness as the background. Observers did not use whole sides of the illusory square. Rather, they mainly used edges of the inducers. We conclude that different types of perceptually interpolated contours are not equally likely to be used to discriminate shapes.

VSS 2006

Date Deadline
Monday, October 17 Call for Abstracts

Monday, October 17 Meeting Registration Opens

Friday, November 4 Call for Satellite Workshops

Friday, December 2 Abstract Submission Deadline

References
Vision Science Society
http://www.vision-sciences.org/

James Joyce : Evelin from "Dubliners"

はじめて読んだのはずいぶん昔のような気がする。陰鬱なダブリンの印象ばかりが記憶に残っている。しかしユリシーズやフィネガンズ・ウェイクを知った後では、読み方も変わるのであろうか。すでに卓抜な表現技巧と劇的構成の妙を小品でも備えている。

References
エヴリン「ダブリンの人々」より Evelin from "Dubliners"
ジェイムス・ジョイス (James Joyce) 作 高木　健　訳
*プロジェクト杉田玄白* http://www.genpaku.org/

MATLABの座標系

下記サイト参照

MATLABでは、グラフ、グラックス、行列と様々な概念を取り入れ座標系を定義している。それぞれ従来の慣習にならい座標系を定義しているため注意が必要である。
MATLABで使用される座標系は、
直交座標系
行列座標系
ピクセル座標系
の3つがある。

直交座標系
直交座標系(Cartesian coordinate system)は、plot,plot3などに使用される座標系でもっとも一般的な座標系である。この系では、最初の成分xは、右方向へ増加し、2番目の成分yは上方向に増加する。原点(0,0)は、下左隅である。

ピクセル座標系
ピクセル座標系(pixel coordinate system)は、ディジタルイメージプロセッシングに使用される一般的な座標系である。これは、画面の左上隅が原点となり最初のx成分が右方向に増加し、y成分が下方向に増加する座標系である。



References
法政大学工学部　小林研究室　MATLABでの座標系について
http://www.ikko.k.hosei.ac.jp/~matlab/mbbok2/coordinate.htm