Subjective contours detection
Basic visual activities are related to edge detection (motion, recognition,...). We show that there are different kinds of edges. The most known and already studied are edges due to luminance variations. After a brief introduction to classical edge-detectors, we introduce another class of edges, the “subjective contours”. We assume end-points as textons as proposed by B. Julesz  and D. Marr . The first step of our algorithm consists in geometric feature (i.e. segments) extraction using the hierarchical Hough transform. The end-points of the detected features are then drawn on a new image. This second “feature map” (of higher level) is then processed in a second step using again the hierarchical Hough transform. The end-points acts as clues indicating the presence of “subjective contours”. We show that there is a relation between the number of clues present in the “feature map” and the pop-out phenomenon of the “subjective contour”.
KeywordsIllusory Contour Subjective Contour Vote Process Hough Space Gestalt Theory
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- D.H. Ballard and C.M. Brown: Computer Vision, Prentice-Hall (1982).Google Scholar
- S. Ben-Yacoub and A. Leonardis: “Making the Hough transform more robust and precise”. submitted to SCIA’97.Google Scholar
- J. Illingworth and J. Jittler: “A survey on the Hough transform”, CVGIP, Vol 44, pp 87–116, (1988).Google Scholar
- B. Julesz: “Preconscious and conscious processes in vision”. Pattern Recognition mechanisms, C. Chagas, R.Gatas, C. Grossberg ( Eds ), Springer-Verlag (1985).Google Scholar
- G. Kanisza: “Organisation in Vision”, Praeger, New-York (1979)Google Scholar
- K. Koffka: “Principles of Gestalt Psychology”, Harcourt-Brace, New-York (1935).Google Scholar
- A. Treisman: “Preattentive processing in vision”. CVGIP, 31, pp 157–157, (1985).Google Scholar
- F. Schumann: “Einige Beobachtungen uber die Zusammenfassung von Gesichtseindrucken zu Einheiten”. Psychologische Studien: 1: pp 1–32, (1904)Google Scholar