Jean-Marc Boi

Bio: Jean-Marc Boi is an academic researcher from Aix-Marseille University. The author has contributed to research in topics: Photogrammetry & Image segmentation. The author has an hindex of 9, co-authored 35 publications receiving 259 citations. Previous affiliations of Jean-Marc Boi include Centre national de la recherche scientifique.

A discrete model for color naming

Abstract: The ability to associate labels to colors is very natural for human beings. Though, this apparently simple task hides very complex and still unsolved problems, spreading over many different disciplines ranging from neurophysiology to psychology and imaging. In this paper, we propose a discrete model for computational color categorization and naming. Starting from the 424 color specimens of the OSA-UCS set, we propose a fuzzy partitioning of the color space. Each of the 11 basic color categories identified by Berlin and Kay is modeled as a fuzzy set whose membership function is implicitly defined by fitting the model to the results of an ad hoc psychophysical experiment (Experiment 1). Each OSA-UCS sample is represented by a feature vector whose components are the memberships to the different categories. The discrete model consists of a three-dimensional Delaunay triangulation of the CIELAB color space which associates each OSA-UCS sample to a vertex of a 3D tetrahedron. Linear interpolation is used to estimate the membership values of any other point in the color space. Model validation is performed both directly, through the comparison of the predicted membership values to the subjective counterparts, as evaluated via another psychophysical test (Experiment 2), and indirectly, through the investigation of its exploitability for image segmentation. The model has proved to be successful in both cases, providing an estimation of the membership values in good agreement with the subjective measures as well as a semantically meaningful color-based segmentation map.

The ROV 3D Project: Deep-Sea Underwater Survey Using Photogrammetry: Applications for Underwater Archaeology

Abstract: In this article, we present an approach for a deep-sea survey based on photogrammetry using a remotely operated underwater vehicle (ROV). A hybrid technique gives us real-time results, sufficient for piloting the ROV from the surface vessel and ensuring a uniform coverage of the site, as well as recording high-definition images using an onboard computer that will later provide a survey with millimetric precision. The measurements are made without any contact and are noninvasive. The time required on-site is minimal and corresponds to the time needed by the ROV to cover the zone. With the photos taken at a frame rate synchronized at 10Hz, the ROV required 2 hours to perform the experiment presented in this article: the survey of the Roman shipwreck Cap Benat 4, at a depth of 328m. The approach presented in this work was developed in the scope of the ROV 3D project. This project, financed by the Fond Unique Interministeriel (FUI) for 3 years, brings together two industrial partners and a research laboratory. Companie Maritime d’Expertise (COMEX) coordinated this project.

Performances Analysis of Underwater Image Preprocessing Techniques on the Repeatability of SIFT and SURF Descriptors

Abstract: ROV 3D project aims at developing innovative tools which link underwater photogrammetry and acoustic measurements from an active underwater sensor. The results will be 3D high resolution surveys of underwater sites. The new means and methods developed aim at reducing the investigation time in situ, and proposing comprehensive and non-intrusive measurement tools for the studied environment. In this paper, we made an investigation to find at first a pre-processing method of underwater images that do not require a priori knowledge of the scene in order to increase the repeatability of SIFT and SURF descriptors and, in a second time, finding a method to compute distances which will be less costly in terms of execution time for finding corresponding points.

Fast Visual Odometry for a Low-Cost Underwater Embedded Stereo System †

Abstract: This paper provides details of hardware and software conception and realization of a stereo embedded system for underwater imaging. The system provides several functions that facilitate underwater surveys and run smoothly in real-time. A first post-image acquisition module provides direct visual feedback on the quality of the taken images which helps appropriate actions to be taken regarding movement speed and lighting conditions. Our main contribution is a light visual odometry method adapted to the underwater context. The proposed method uses the captured stereo image stream to provide real-time navigation and a site coverage map which is necessary to conduct a complete underwater survey. The visual odometry uses a stochastic pose representation and semi-global optimization approach to handle large sites and provides long-term autonomy, whereas a novel stereo matching approach adapted to underwater imaging and system attached lighting allows fast processing and suitability to low computational resource systems. The system is tested in a real context and shows its robustness and promising future potential.

Underwater programmetry for archaeology and marine biology: 40 years of experience in Marseille, France

Abstract: Since 19,3 archeology and computer science have developed close ties in Marseille. Two departments (computer science and archaeology) from the French National Centre for Scientific Research (CNRS) in Marseille started working together and laid the cornerstone of the Computer Applications and Quantitative Methods in Archaeology (CAA) community. Marseille also has the advantage of being located in a very interesting place on the Mediterranean Sea and being the home to several famous laboratories, such as the French Cultural Heritage Department (DRASSM) or private companies like COMER. In 1980 they performed a series of explorations of a deep-sea wreck with the help of COMER and DRASSM. More recently, ten years ago, the Centre d'Oceanologie de Marseille (COM) started using underwater photogrammetry to survey and monitor red coral populations in situ. In this paper we present new advances in underwater photogrammetry for archaeology and marine biology based on forty years of experience. The survey described in this article does not only discuss the acquisition of 3D points in difficult conditions but also linking archaeological knowledge to the surveyed geometry. This approach needed to combine automatic data processing and offered the opportunity to experts, archaeologists or biologists, to insert knowledge in the process. After an introduction to the history of computer science and archaeology, we will present related work in underwater archaeology and marine biology. The last section is dedicated to two recent experiments in Marseille, based on recent developments in automatic photogrammetry: a World War II plane wreck, surveyed using both acoustic and optical sensors, and a survey used to monitor red coral growth over several years.

Learning Color Names for Real-World Applications

Abstract: Color names are required in real-world applications such as image retrieval and image annotation. Traditionally, they are learned from a collection of labeled color chips. These color chips are labeled with color names within a well-defined experimental setup by human test subjects. However, naming colors in real-world images differs significantly from this experimental setting. In this paper, we investigate how color names learned from color chips compare to color names learned from real-world images. To avoid hand labeling real-world images with color names, we use Google image to collect a data set. Due to the limitations of Google image, this data set contains a substantial quantity of wrongly labeled data. We propose several variants of the PLSA model to learn color names from this noisy data. Experimental results show that color names learned from real-world images significantly outperform color names learned from labeled color chips for both image retrieval and image annotation.

Full-Reference Image Quality Metrics: Classification and Evaluation (Foundations and Trends in Computer Graphics and Vision)

Abstract: The wide variety of distortions that images are subject to during acquisition, processing, storage, and reproduction can degrade their perceived quality. Since subjective evaluation is time-consuming, expensive, and resource-intensive, objective methods of evaluation have been proposed. One type of these methods, image quality (IQ) metrics, have become very popular and new metrics are proposed continuously. This paper aims to give a survey of one class of metrics, full-reference IQ metrics. First, these IQ metrics were classified into different groups. Second, further IQ metrics from each group were selected and evaluated against six state-of-the-art IQ databases.

Underwater Photogrammetry for Archaeology

Abstract: Archaeological excavations are often irreversibly destructive, so it is important to accompany them with detailed documentation reflecting the accumulated knowledge of the excavation site. This documentation is usually iconographic and textual. Graphical representations of archaeological sites such as drawings, sketches, watercolors, photographs, topography, and photogrammetry are indispensable for such documentation and are an intrinsic part of an archaeological survey. However, as pointed out by Olivier Buchsenschutz in the introduction to the symposium Images and archaeological surveys, in Arles, France, in 2007 (Buchsenschutz, 2007, Introduction page 5), even a very precise drawing only retains certain observations that support a demonstration, just as a speech retains only some arguments, but this choice is not usually explicit. This somewhat lays the foundation of this work: a survey is both a metrics document and an interpretation of the site by archaeologist.

Geometric and Optic Characterization of a Hemispherical Dome Port for Underwater Photogrammetry.

Abstract: The popularity of automatic photogrammetric techniques has promoted many experiments in underwater scenarios leading to quite impressive visual results, even by non-experts. Despite these achievements, a deep understanding of camera and lens behaviors as well as optical phenomena involved in underwater operations is fundamental to better plan field campaigns and anticipate the achievable results. The paper presents a geometric investigation of a consumer grade underwater camera housing, manufactured by NiMAR and equipped with a 7′′ dome port. After a review of flat and dome ports, the work analyzes, using simulations and real experiments, the main optical phenomena involved when operating a camera underwater. Specific aspects which deal with photogrammetric acquisitions are considered with some tests in laboratory and in a swimming pool. Results and considerations are shown and commented.