Xavier Lladó Bardera



  Surface Texture Analysis

  • Motivation:  Reduce the texture classification errors caused by changes in imaging geometries: illumination direction, camera distance, etc.


  • Model-based Texture classification
    • Virtual database creation: we create a set of virtual images which is used as a reference for the classification purpose. Colour Photometric Stereo is used to recover the surface information, as well as to render new images of the same surface texture under different directions of illumination.
    • Recognition procedure
        - Learning process (Feature selection/ Feature evaluation)
        - Classification process (Nearest Neighbour classifer)
    • Illuminant tilt angle prediction

 Texture Database

Our texture database consists of twenty five different textures. We used real textures commonly found in our every day life: simple textures based on different cloth, paper, etc, and other textures formed by repeating primitives of foods such as beans, lentils, spaghetti, chips, etc.

The database contains:

  • Different Colour Photometric Stereo sets of images captured at two distances A and B (longer than A).
  • Testing images at distance A and B. The images were captured using 12 or 24 illuminant tilt angles between 0º and 360º incremented by steps of 15º or 30º. All surfaces were lit at an elevation angle of 55º.
  Last update: September, 2003