PeopleofSuperintelligence

Researcher

Serge G. Castan

Serge Castan's research in Toulouse joined computer vision and image understanding with parallel hardware for image processing. His early work included a 1975 skeletonization algorithm with André Nabonne, and in 1984 he presented both the SYMPATI multiprocessor and a perspective-corrected stereo matching method at the GRETSI colloquium. He co-directed the CERFIA laboratory with Guy Pérennou, one of the units merged into IRIT in 1990, and with Jun Shen published “An optimal linear operator for step edge detection” in 1992. The International Association for Pattern Recognition named him a Fellow in 1994 for contributions in computer vision, image understanding and parallel architecture for image processing. In 2004, he recalled for Interstices the early days of the field, when digitizing a single image took several seconds.

Works
38
Citations
649
h-index
9

Publication numbers from OpenAlex, as of 22 October 2026.

Timeline

  1. 1975

    A skeletonization algorithm

    In 1975, he and André Nabonne publish “Un algorithme de squelettisation opèrant par tests locaux sur des suites de voisinages successifs”, a skeletonization algorithm built on local tests over successive neighbourhoods.

  2. 1984

    The SYMPATI multiprocessor

    At the 1984 GRETSI colloquium, he presents “Structures parallèles en traitement d'images” with J. L. Basille and J. Y. Latil. The paper studies the limits of MIMD structures in image processing and gives simulation results for SYMPATI, a multiprocessor with a SIMD level for local operations and a MIMD level for region processing.

  3. 1984

    Perspective stereo vision

    With Jun Shen, he also presents “Stéréo vision par projections perspectives” at the 1984 GRETSI colloquium. Their algorithm matches stereo images while correcting the perspective distortion between the two views.

  4. 1990

    CERFIA joins IRIT

    In 1990, CERFIA, the Toulouse unit for cybernetics, pattern recognition and intelligence that he directs with Guy Pérennou, merges with other units to form IRIT, the Institut de recherche en informatique de Toulouse.

  5. 1992–1993

    Optimal edge detection operators

    With Jun Shen, he publishes “An optimal linear operator for step edge detection” in 1992. The pair follow it in 1993 with “Towards the unification of band-limited derivative operators for edge detection” in Signal Processing.

  6. 1994

    An IAPR Fellowship

    The International Association for Pattern Recognition names him a Fellow in 1994 for contributions in computer vision, image understanding and parallel architecture for image processing, and for service to the IAPR.

  7. 1995

    The KBUP95 program committee

    In 1995, he serves on the program committee of KBUP95, the first international workshop on knowledge-based systems for the reuse of program libraries, held at INRIA Sophia Antipolis in November 1995. The call lists him with IRIT Toulouse.

  8. February 2004

    Recalling early image processing

    In February 2004, he describes the early years of image processing to the science site Interstices. Digitizing one image took several seconds, he recalls, and around 1975 researchers loaded punch-card decks in the morning and hoped for a result by noon.

Career

  1. 1990Institute for Research in Computer Science of ToulouseCo-Director, Member
  2. 1990–2003Université Toulouse Capitole
  3. 1986–2005Université Toulouse III - Paul Sabatier

From the biography and OpenAlex affiliations (the years of papers that list the organization), so some years are approximate.

Most-cited works

  1. An optimal linear operator for step edge detection1992 · CVGIP Graphical Models and Image Processing · 378 citations
  2. New edge detection methods based on exponential filter2002 · International Conference on Pattern Recognition · 44 citations
  3. A new correlation criterion based on gradient fields similarity1996 · International Conference on Pattern Recognition · 41 citations
  4. Optimal filter for edge detection methods and results1990 · Lecture notes in computer science · 35 citations
  5. Towards the unification of band-limited derivative operators for edge detection1993 · Signal Processing · 27 citations

From OpenAlex, as of 21 October 2026.

  1. More people shaping AI studied at Massachusetts Institute of Technology than at any other institutionIncludes Université Toulouse III - Paul Sabatier. We estimate where the people shaping AI studied and where their careers led. Massachusetts Institute of Technology leads with 467 former students, including 291 recorded doctorates.
  2. The company share of AI researchers’ top papers was 31% in 2020–2024 and 8% in 1970–1974Includes Université Toulouse III - Paul Sabatier. We estimate where the people shaping AI worked when their most-cited papers appeared: the company share was 31% in 2020–2024 and 8% in 1970–1974, and Google led all organizations in 2020–2024.
  3. The Massachusetts Institute of Technology trained or employed 44 of the 187 AI major-prize winners, more than any other universityIncludes Université Toulouse III - Paul Sabatier. The Massachusetts Institute of Technology trained or employed 44 of the 187 AI major-prize winners, more than any other university. We compare doctorate and 5+ year employment links, career timing and current workplaces for 187 major-prize and 1,111 best-paper winners.
  4. Google has the highest combined h-index among AI organizationsIncludes Université de Toulouse. We estimate that Google holds the highest combined h-index at 8,016, while universities account for 73% of the deduplicated total across AI organizations.

Colleagues

People with dated positions at the same organization in the same years.

Sources and credits

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  1. Rankless | Serge Castan rankless.org. Checked 21 October 2026.
  2. GRETSI : Colloque Gretsi 1984 gretsi.fr. Checked 21 October 2026.
  3. Institut de recherche en informatique de Toulouse — Wikipédia fr.wikipedia.org. Checked 21 October 2026.
  4. Chronological List of IAPR Fellows – International Association for Pattern Recognition iapr.org. Checked 21 October 2026.
  5. VISION-LIST digest 14.11 groups.google.com. Checked 21 October 2026.
  6. Histoire du traitement d'images - Interstices interstices.info. Checked 21 October 2026.