Guillaume Touya

Institut national de l’information géographique et forestière | IGN · ENSG-Géomatique

In the cartographic navigation process, enhancing the efficiency of panning and zooming operations is crucial for users trying to locate their target. Due to the changes in maps at different zoom levels, and the reduction of the visualised extent during a zoom-in, the map user often lacks visual cues to indicate where exactly the current map view i...

When a fast kinetic natural disaster occurs, it is crucial that crisis managers quickly understand the extent of the situation, especially through the development of “big picture” maps. For many years, great efforts have been made to use social networks to help build this situational awareness. While there are many models for automatically extracti...

This paper reports two experiments for the design of anchored pan-scalar maps. Anchoring pan-scalar maps means improving the saliency and memorability of some cartographic elements, i.e. the pan-scalar anchors, to enhance the navigational cues that can be used for self-localization during or after a zoom in a map. Within this article, concrete exam...

Saliency models try to predict the gaze behaviour of people in the first seconds of their observation of an image. To assess how much these models can perform to predict saliency in maps, we lack a ground truth to compare to. This paper proposes EyeCatchingMaps, an open dataset that can be used to benchmark saliency models for maps. The dataset has...

Bees can communicate the location of interesting resources to forage to their nestmates by performing what we call a waggle dance. Being able to precisely decode the information conveyed with waggle dances would help biologists, ecologists, beekeepers, and even decision-makers to limit the current decline of bees. The challenge addressed in this pa...

While maps have been evolving towards more interactivity and pan-scalar display, their design did not change this much, lacking progressiveness between the numerous maps at different zoom levels. Drawing inspiration from the well-established theories of comics and cinema, this article explores the essential mechanics of these mediums, particularly...

Automated map generalization has been a major area of research for decades but has still not reached maturity. Besides the needs for more adaptive algorithms, a fundamental question remains: How can we transfer human generalization knowledge into a computational system more effectively? Previous efforts do not seem capable to fully overcome the “kn...

Machine learning is increasingly used as a computing paradigm in cartographic research. In this extended editorial, we provide some background of the papers in the CaGIS special issue Machine Learning in Cartography with a special focus on pattern recognition in maps, cartographic generalization, style transfer, and map labeling. In addition, the p...

Les enquêtes et questionnaires reposent souvent sur l’utilisation de supports papier, et les cartes ne font pas exception. En effet, ces dernières permettent une grande flexibilité, notamment en termes d’annotations, de dessins, etc. Mais la conversion et l’exploitation des données ainsi récoltées dans un SIG peuvent s’avérer fastidieuses, et cela...

When you zoom in or out of current multi-scale cartographic applications, it is common to feel lost and disoriented for a few seconds because dimensions and map symbols have changed. To make the exploration of these multi-scale maps more fluid, one option is to design maps where the transformations due to scale change are more progressive. This pap...

The automation of map generalization has been an important research subject for decades but is not fully solved yet. Deep learning techniques are designed for various image generation tasks, so one may think that it would be possible to apply these techniques to cartography and train a holistic model for end-to-end map generalization. On the contra...

Maps and their usage have widely evolved recently, to become more and more interactive, multi-scale and accessible. However, the design of maps did not change so much, leading to the following two problems: (1) in theory, it is not formalised how to create a good map in this context, (2) in practice, the most used maps are not good considering the...

In order to design better pan-scalar maps, i.e. interactive, zoomable, multi-scale maps, we need to understand how they are perceived, understood, processed, manipulated by the users. This paper reports an experiment that uses an eye-tracker to analyse the gaze behaviour of users zooming and panning into a pan-scalar map. The gaze data from the exp...

Poster de vulgarisation scientifique journée de la recherche IGN 2023. Inspiré de la theorie des ancres de Couclelis et collègues, ce poster présente une methodologie d'analyse de presence et persistence d'élements cartographiques à travers differentes explorations cartographiques.

Honeybees are known for their ability to communicate about resources in their environment. They inform the other foragers by performing specific dance sequences according to the spatial characteristics of the resource. The purpose of our study is to provide a new tool for honeybees dances recording, usable in the field, in a practical and fully aut...

Disorientation is a common feeling for all users of zoomable multi-scale maps, even for those with good orientation and spatial skills. We make the assumption that this problem is mainly due to the desert fog effect, documented in human–computer interaction within multi-scale zoomable environments. Starting with a collection of reported experiences...

Most of the maps used today are what we call pan-scalar maps, i.e. interactive zoomable applications comprised of numerous maps of a particular area at different zoom levels (i.e. scales). We argue that such maps require a pan-scalar map design, which may differ significantly from established map design axioms and standards. This review is twofold....

Map generalisation is a process that transforms geographic information for a cartographic at a specific scale. The goal is to produce legible and informative maps even at small scales from a detailed dataset. The potential of deep learning to help in this task is still unknown. This article examines the use case of mountain road generalisation, to...

Tactile cartography has always been a niche topic, but even among tactile cartographers, little attention has been paid to thematic tactile maps. Thematic maps are used in education and the lack of such materials makes it difficult to fulfill particular subjects’ curriculums. In this research, we propose a methodology for automatic compilation of l...

Accessibility to tactile maps is limited due to their expensive and time-consuming development. Acceleration of their production requires standardized design guidelines that consider symbol design and production methods. In this paper, based on a review of research and best practice, we summarize knowledge on how to design tactile maps properly and...

The adoption of technology in urban participatory planning with tools such as Virtual Geographic Environments (VGE) promises a broader engagement of urban dwellers, which should ultimately lead to the creation of better cities. However, the authorities and urban experts show hesitancy in endorsing these tools in their practices. Indeed, several par...

The shapes and patterns of the road network of a topographic map provide important visual cues when interpreting the map and moving between scales in interactive environments. The ’city ring road’ is an example of a road structure we might use in the recognition and characterisation of a city. Our goal is the automatic identification (and preservat...

Recently, many researchers tried to generate (generalised) maps using deep learning, and most of the proposed methods deal with deep neural network architecture choices. Deep learning learns to reproduce examples, so we think that improving the training examples, and especially the representation of the initial geographic information, is the key is...

Crossing an intersection is a challenge for visually impaired people. While tactile maps can be a medium for appropriating this complex space, they benefit from being complemented by audio information. In this paper we propose a data model to describe an intersection, the paths that allow to cross it, and their accessibility attributes. We also pre...

Deep learning techniques have recently been experimented for map generalization. Although promising, these experiments raise new problems regarding the evaluation of the output images. Traditional map generalization evaluation cannot directly be applied to the results in a raster format. Additionally, the internal evaluation used by deep learning m...

Explorer la théorie des ancres et les espaces cognitifs dans la cartographie multi-échelle. Maïeul GRUGET & Guillaume TOUYA LASTIG, Univ Gustave Eiffel, ENSG, IGN Votre carte mentale pourrait modifier la manière dont vous percevez une cartographie multi-échelle. Vers un zoom cognititif ancré ?

Neural Style Transfer is a Computer Vision topic intending to transfer the visual appearance or the style of images to other images. Developments in deep learning nicely generate stylized images from texture-based examples or transfer the style of a photograph to another one. In map design, the style is a multi-dimensional complex problem related t...

The spread of COVID-19 has motivated a wide interest in visualization tools to represent the pandemic’s spatio-temporal evolution. This tools usually rely on dashboard environments which depict COVID-19 data as temporal series related to different indicators (number of cases, deaths) calculated for several spatial entities at different scales (coun...

For the past twenty years, the adoption of Virtual Geographic Environments is thriving. This democratization is due to numerous new opportunities offered by this medium. However, in participatory urban planning these interactive 3D geovisualizations are still labeled as very advanced means, and are only scarcely used. The involvement of citizens in...

LostInZoom is a new research project that will seek to design novel ways of zooming into multi-scale maps, to overcome the desert fog effect that occurs with current multi-scale cartography techniques. The desert fog effect makes you feel lost for a few seconds after a zoom in or out, because the map has changed. The idea developed in this project...

While the recent progress on automated generalisation helped National Mapping Agencies to derive topographic maps more and more quickly, there are still practical cartographic issues that require attention. For instance, embankments are represented with line symbols showing the slope of the embankment. This paper proposes an automated algorithm cal...

The spatial analysis of health data usually raises geoprivacy issues. Due to the virulence of COVID-19, scientists and crisis managers do need to analyze the distribution and spread of the disease with spatially precise data. In particular, it is useful to locate each case on a map to identify clusters of cases. To allow such analyses without breac...

Cartographic generalization is a process similar to text summarization that transforms a map when scale is reduced. Cartographic generalization simplifies the map content while preserving as much as possible the initial characteristics and spatial relations of the map. The automation of this process requires a deep understanding of the context of e...

This article presents how a generative adversarial network (GAN) can be employed to produce a generalised map that combines several cartographic themes in the dense context of urban areas. We use as input detailed buildings, roads, and rivers from topographic datasets produced by the French national mapping agency (IGN), and we expect as output of...

The use of deep learning techniques for map generalisation raises new problems regarding the evaluation of the results: (1) images are used as input/output instead of vector data; (2) the deep learning processes do not guarantee results that follow cartographic principles; (3) the deep learning models are black boxes that hide the causal mechanisms...

Les courbes de niveau sont l'un des éléments clés des cartes topographiques, car elles facilitent la compréhension du terrain. Mais elles ne sont plus dessinées par des cartographes, elles sont la plupart du temps automatiquement dérivées de modèles numériques de terrain (MNT). Malgré de réels progrès dans cette dérivation automatisée, certains pay...

Background: The spatio-temporal analysis of cases is a good way an epidemic, and the recent COVID-19 pandemic unfortunately generated a huge amount of data. But analysing this raw data, with for instance the address of the people who contracted COVID-19, raises some privacy issues, and geomasking is necessary to preserve both people privacy and the...

The spatial analysis of health data usually raises geoprivacy issues. But with the virulence of COVID-19, scientists and crisis managers do need to analyse the spatio-temporal distribution and spreading of the disease with spatially precise data. In particular, it is useful to locate each case on a map to identify clusters of cases in space and tim...

Visually impaired people cannot use classical maps but can learn to use tactile relief maps. These tactile maps are crucial at school to learn geography and history as well as the other students. They are produced manually by professional transcriptors in a very long and costly process. A platform able to generate tactile maps from maps scanned fro...

Though Volunteered Geographic Information (VGI) has the advantage of providing free open spatial data, it is prone to vandalism, which may heavily decrease the quality of these data. Therefore, detecting vandalism in VGI may constitute a first way of assessing the data in order to improve their quality. This article explores the ability of supervis...

Cartographic generalization research has focused almost exclusively in recent years on topographic mapping, and has thereby gained an incorrect reputation for having to do only with reference or positional data. The generalization research community needs to broaden its scope to include thematic cartography and geovisualization. Generalization is n...

Among cartographic generalisation problems, the generalisation of sinuous bends in mountain roads has always been a popular one due to its difficulty. Recent research showed the potential of deep learning techniques to overcome some remaining research problems regarding the automation of cartographic generalisation. This paper explores this potenti...

Spatial analysis and pattern recognition with vector spatial data is particularly useful to enrich raw data. In road networks, for instance, there are many patterns and structures that are implicit with only road line features, among which highway interchange appeared very complex to recognize with vector-based techniques. The goal is to find the r...

Mapping applications display multi-scale maps where zooming in and out triggers the display of different maps at different scales. Multi-scale maps strongly augmented the potential uses of maps, compared to the traditional single-scaled paper maps. But the exploration of the multi-scale maps can be cognitively difficult for users because the conten...

Les cartes tactiles photoréalistes sont un des outils mobilisés par les personnes en situation de déficience visuelle pour appréhender leur environnement urbain proche, notamment dans le cadre de la mobilité, pour la traversée de carrefours par exemple. Ces cartes sont aujourd’hui principalement fabriquées artisanalement. Dans cet article, nous pro...

Dans un contexte où le vandalisme de l’information géographique volontaire constitue une réelle menace pour la qualité des données, cet article propose une technique permettant de le détecter. Tout d’abord, nous examinons les différentes définitions du vandalisme, mettant en avant la complexité de cette notion. Une étude des cas déjà avérés de vand...

Contour lines are a key features of topographic maps as they make the comprehension of terrain more easy. But they are no longer drawn by cartographers, they are mostly automatically derived from digital terrain models. Despite real progress in this automated derivation, some specific terrain landscapes remain incorrectly depicted with such techniq...

Automatic map generalization is a complex task that is still a research problem and requires the development of research prototypes before being usable in productive map processes. In the meantime, reproducible research principles are becoming a standard. Publishing reproducible research means that researchers share their code and their data so tha...

The impetus induced by the development of multi-scale, multi-style maps calls for thinking our resources and protocols with greater interoperability. In the field of toponymy, this requires, in particular, thinking of categories and their structuring with more granularity. Assuming that typography, as a device for visualizing toponyms, is a tool wh...

The automation of map generalization has been keeping researchers in cartography busy for years. Particularly great progress was made in the late 90s with the use of the multi-agent paradigm. Although the current use of automatic processes in some national mapping agencies is a great achievement, there are still many unsolved issues and research se...

This paper aims to qualify the behaviour of contributors to OpenStreetMap (OSM), a volunteered geographic information (VGI) project, through a multigraph approach. The main purpose is to reproduce contributor's interactions in a more comprehensive way. First, we define a multigraph that combines existing spatial collaboration networks from the lite...

Dans un contexte où le vandalisme de l'information géographique volontaire constitue une réelle menace pour la qualité des données, cet article propose d'explo-rer les diérentes techniques permettant de le détecter. Tout d'abord, nous tâchons d'examiner les diérentes définitions du vandalisme, mettant en avant la complexité de cette notion. Puis, n...

Vandalism is a phenomenon that has affected by now the digital domain, in particular in the context of Volunteered Geographic Information projects. This paper aims at proposing a methodology to detect vandalism in the OpenStreetMap project. First, an analysis of related works sheds light on the lack of consensus when it comes to defining vandalism...

Tactile maps are essential tools for visually impaired people to comprehend space and to support the simple pedestrian trips made difficult by their disability. Tactile maps are created manually and printed by specialists, and it takes a large amount of time to create a new one, which prevents using them on demand for everyday use. As a consequence...

This talk introduces the results of MapMuxing, a collaborative project aiming at providing cartographic multiplexing techniques for crisis management. The project grouped researchers in geovisualisation, computer-human interaction and risk geography to better understand visualisation needs and design cartographic continuum and multiplexing techniqu...

Map users may have issues to achieve multi-scale navigation tasks, as cartographic objects may have various representations across scales. We assume that adding intermediate representations could be one way to reduce the differences between existing representations, and to ease the transitions across scales. We consider an existing multiscale map o...

Automatic map generalization requires the use of computationally intensive processes often unable to deal with large datasets. Distributing the generalization process is the only way to make them scalable and usable in practice. But map generalization is a highly contextual process, and the surroundings of a generalized map feature needs to be know...

Geoportals and geovisualization tools provide to users various cartographic abstractions that describe differently a geographical space. Our purpose is to be able to design cartographic continuums, i.e. a set of in-between maps allowing users to navigate between two topographic styles. This paper addresses the problem of the interpolation between t...

Label placement is a tedious task in map design, and its automation has long been a goal for researchers in cartography, but also in computational geometry. Methods that search for an optimal or nearly optimal solution that satisfies a set of constraints, such as label overlapping, have been proposed in the literature. Most of these methods mainly...

Modéliser les interactions sociales au sein de projets de cartographie volontaire et citoyenne nécessite de définir ce qui relie les contributeurs entre eux dans le temps et l'espace. Dans un souci de réalisme, plu-tôt que d'étudier un seul type de relation, nous choisissons de construire un réseau social multi-couche contenant différents types d'i...

Cartographic generalization is a highly local and contextual process where decisions are taken locally to better adjust the transformations used to the local geography. Thus, carto-graphic generalization fits well with the multi-agents paradigm that promotes decentralized and autonomous decision-making. The past years of research in cartographic ge...