Yann GAVET
Dr. HDR
Ecole Nationale Supérieure des Mines de Saint-Etienne

Internet databases

Modelisation and simulation of surfaces, mosaics and textures

Voronoi diagrams are classically used to model mosaic patterns (like grains or cells). In the CorImMo 3D project (ANR TecSan 2012), the study of random fields allows us to randmly determine germs as well as distances to generate a spatial partition of the 2D or 3D space. The concepts and tools are based on:
  • random fields theory (covariance function, statistical moments including the skewness and kurtosis)
  • integral geometry (e.g., Minkowski functionals: area, perimeter and connectivity number for 2D fields; volume, surface area, mean breadth and connectivity number for 3D fields)
  • and mathematical morphology (e.g., openings and closures, skeletons, watersheds, granulometry).

Mosaics

The corneal endothelium is constituted of non-regenerative cells. We have proposed:
  • Segmentation methods based on human visual properties (Gestalt and Marr theories)
  • Segmentation evaluation tool, called epsilon dissimilarity criterion, tolerant to visual and spatial variations
  • 3D Reconstruction method (shape from focus), applied to corneal endothelium.
3D Cornea Surface
mosaic
segmented cornea

CoLIP: Color Logarithmic Image Processing

Impression au soleil levantClaude Monet: impression au soleil levant.
Eglise d'Auvers sur OiseVan Gogh: l'Eglise d'Auvers sur Oise
Transfert de couleursColor transfer.
The Color Logarithmic Image Processing (CoLIP) is a recently introduced (2011) extension of the LIP mathematical framework based on abstract linear mathematics which provides a set of specific algebraic and functional operations that can be applied to the processing of color images valued in a bounded range. The CoLIP approach has been proved to be psycho-physically consistent with several laws and characteristics of the human color perception.
Successful applications have been reported on the white balance correction in color images.