Human facial expressions change dynamically, so their recognition / analysis should be conducted by accounting for the temporal evolution of face deformations either in 2D or 3D. While abundant 2D video data do exist, this is not the case in 3D, where few 3D dynamic (4D) datasets were released for public use. The negative consequence of this scarcity of data is amplified by current deep learning based-methods for facial expression analysis that require large quantities of variegate samples to be effectively trained. With the aim of smoothing such limitations, in this paper we propose a large dataset, named Florence 4D, composed of dynamic sequences of 3D face models, where a combination of synthetic and real identities exhibit an unprecedented variety of 4D facial expressions, with variations that include the classical neutral-apex transition, but generalize to expression-to-expression. All these characteristics are not exposed by any of the existing 4D datasets and they cannot even be obtained by combining more than one dataset. We strongly believe that making such a data corpora publicly available to the community will allow designing and experimenting new applications that were not possible to investigate till now. To show at some extent the difficulty of our data in terms of different identities and varying expressions, we also report a baseline experimentation on the proposed dataset that can be used as baseline.
翻译:人类面部表达方式的变化动态,因此,对人类面部表达方式的识别/分析应当以2D或3D中面部变形的时间演变为考量2D或3D中面部变形的时间演变来进行。虽然存在丰富的2D视频数据,但3D中的情况并非如此,其中为公众使用而发布的3D动态(4D)数据集很少。数据稀缺的负面后果由于目前用于面部表达分析的深层学习基础方法而更加突出,而这些方法要求大量变异样本进行有效培训。为了平滑这些局限性,我们在本文件中提议建立一个大型数据集,名为佛罗伦萨4D,由3D面部的动态序列组成,其中合成和真实身份的组合展示了前所未有的4D面部面部表达形式,其中的变化包括典型的中式对映转换,但一般化为表达式。所有这些特征都未通过现有的4D表达式分析而暴露出来,甚至无法通过合并一个以上的数据集来获得。我们坚信,向社区公开提供这样的数据将允许设计和实验新的应用程序,其中的3D面部的动态序列序列序列将展示出前所未有的四维难度。