When memory was measured in kilobytes: The art of efficient vision

Summary

By Mathilde Fichen In the early days of computer vision, when memory was scarce and every byte counted, innovation thrived under constraint. “An Efficient Chain-Linking Algorithm,” developed at Inria in the late 1980s, is a brilliant example of this spirit. Now preserved and shared by Software Heritage, this compact yet powerful piece of C code showcases how elegance and efficiency went hand in hand in outlining the future of image processing—one pixel chain at a time. The code resulted from research work carried out between 1985 and 1991 at Inria, by Gérard Giraudon (research and principal investigator), Philippe Garnesson (a PhD student), and Patrick Cipière (software engineer). Down in sunny Sophia Antipolis, a tech park 20 minutes inland from Antibes, the team tackled computer vision with a distinctly local flavor. They called themselves PASTIS, a playful nod to the anise drink. Still, the acronym – Scene Analysis and Symbolic Image Processing Project (Projet d’Analyse de Scène et de Traitement d’Image Symbolique) – hinted at their serious mission. Preserving Inria legacy software The effort to preserve this source code is part of a broader initiative to preserve the legacy codes of Inria (France’s National Institute for Research in Digital Science and Technology), launched in 2023 in a joint effort of Software Heritage, Inria Alumni, and Inria. The project to preserve Inria’s legacy software started by reaching out to the institute’s community, past and present, through a survey (as detailed in our iPres article.) This initial outreach informed a dedicated, hands-on workshop in 2024, which kicked off the practical work of exploring these historical codes. The current focus is on securely archiving the important legacy software we’ve identified within Software Heritage. Sharing the stories behind these codes with the broader community is just as vital. The recovery of some code has been surprisingly straightforward. For instance, the code for “An Efficient Chain...