Call For Participation:
SHREC 2008 - Shape Retrieval Contest of 3D Face Scans

Introduction

The general objective of SHREC is to evaluate the effectiveness of 3D-shape retrieval algorithms. This shape retrieval contest focusses on the retrieval of 3D face models using geometric shape information only. Insight in the performance of face retrieval algorithms may lead to better face recognition methods.

Task description

The task set for the 3D face retrieval contest is to retrieve a ranked list of similar 3D face scans, given a query 3D face, based on the shape characteristics of the 3D faces (no other aspects such as color). The collection to search in consists of 3D triangular face scans.

Data set

The data set used in this contest is a subset of GavabDB: a 3D Face Database[1]. The GavabDB consists of laser range scan from 61 subjects acquired with the Minolta VI-700 laser range scanner. Our subset contains for each of these 61 subjects 7 different scans, namely two "frontal", one "look-up", one "look-down", one "smile", one "laugh", one "random expression". Each of these 427 scans must be used to query the data set, constructing a ranked list with dissimilarity values in the process. The goal is to retrieve for each query as many relevant items (scans of the same subject) as possible on top of the ranked list.
For a fair comparison of 3D face retrieval methods, all scans are already face pose normalized in such a way that the localized tip of the nose is placed in the origin. This way participants can apply their face matching method directly to the data, and preprocessing steps such as face cropping can be applied very easily.
To download an example scan click here.

Evaluation Methodology

The retrieval result must be a ranked list for each query in which all face models from the database are assigned a dissimilarity value. Notice that the lower the dissimilarity is, the more you trust the similarity. These ranked lists will be assessed by a number of performance measures, such as precision and recall, cumulative gain, etc. The relevance assessments will be done automatically using a classification of relevant and not relevant items.

Procedure

The following list is a step-by-step description of the activities:
  1. The participants must register by sending a message to shrec@cs.uu.nl. Early registration is encouraged, so that we get an impression of the number of participants at an early stage.
  2. The database will be made available via this website. Similarly the query set will be made available, against which the evaluation will be run.
  3. Participant submit the ranked lists for each query per email. Up to 5 ranked lists may be submitted, resulting from different runs. Each run may be a different algorithm, or a different parameter setting.
  4. The relevance assessments will be done automatically.
  5. The organization will release the relevance judgments and evaluation scores of all the runs.
  6. The participants write a short paper describing their method and commenting the evaluation results.
  7. The description of the methods and the evaluation scores are presented at SMI'08.

Schedule

  • Feb 25 - Call for participation.
  • March 9 - Please register before this date.
  • March 9 - Distribution of the final face database and the query set. Participants can start the retrieval.
  • March 16 - Submission of results (ranked lists) and a short paper draft describing the method(s).
  • March 17 - Distribution of relevance judgments and evaluation scores.
  • March 24 - Submission of final short papers for the contest proceedings.
  • March 26 - Track is finished, and results are ready for inclusion in the SMI'08 proceedings.
  • June 4-6 - Results presented at a session of SMI'08, proceedings available.

    Organization

    The track of SHREC 2008 called "Shape Retrieval Contest of 3D Face Scans" is organized by Mohamed Daoudi (Telecom Lille1), Frank ter Haar and Remco Veltkamp (Utrecht University). SHREC 2008 is an initiative of the Network of Excellence AIM@SHAPE, http://www.aimatshape.net/. To contact the organizers, send a message to shrec@cs.uu.nl. The results are presented at a special session of SMI'08, Shape Modeling International, http://www.cs.sunysb.edu/smi08/.

    [1] Moreno, A.B., Sánchez, A., 2004. GavabDB: a 3D Face Database. Workshop on Biometrics on the Internet COST275, Vigo, March 25-26, 77-85.