School of Control Science and Engineering, Shandong University, Jinan 250061, China.
Sensors (Basel). 2017 Mar 29;17(4):712. doi: 10.3390/s17040712.
In the pattern recognition domain, deep architectures are currently widely used and they have achieved fine results. However, these deep architectures make particular demands, especially in terms of their requirement for big datasets and GPU. Aiming to gain better results without deep networks, we propose a simplified algorithm framework using fusion features extracted from the salient areas of faces. Furthermore, the proposed algorithm has achieved a better result than some deep architectures. For extracting more effective features, this paper firstly defines the salient areas on the faces. This paper normalizes the salient areas of the same location in the faces to the same size; therefore, it can extracts more similar features from different subjects. LBP and HOG features are extracted from the salient areas, fusion features' dimensions are reduced by Principal Component Analysis (PCA) and we apply several classifiers to classify the six basic expressions at once. This paper proposes a salient areas definitude method which uses peak expressions frames compared with neutral faces. This paper also proposes and applies the idea of normalizing the salient areas to align the specific areas which express the different expressions. As a result, the salient areas found from different subjects are the same size. In addition, the gamma correction method is firstly applied on LBP features in our algorithm framework which improves our recognition rates significantly. By applying this algorithm framework, our research has gained state-of-the-art performances on CK+ database and JAFFE database.
在模式识别领域,深度架构目前被广泛应用,并取得了很好的效果。然而,这些深度架构有其特殊的要求,特别是在数据集和 GPU 的要求方面。为了在不使用深度网络的情况下获得更好的结果,我们提出了一种简化的算法框架,该框架使用从人脸显著区域提取的融合特征。此外,该算法的结果优于一些深度架构。为了提取更有效的特征,本文首先在人脸定义显著区域。本文将人脸相同位置的显著区域归一化为相同大小;因此,可以从不同的主体中提取出更相似的特征。从显著区域提取 LBP 和 HOG 特征,通过主成分分析(PCA)降低融合特征的维度,并应用多个分类器同时对六个基本表情进行分类。本文提出了一种使用峰表达帧与中性脸相比的显著区域定义方法。本文还提出并应用了归一化显著区域的思想,以对齐表达不同表情的特定区域。结果,从不同主体中找到的显著区域大小相同。此外,本文在算法框架中首次应用了伽马校正方法,大大提高了识别率。通过应用这个算法框架,我们的研究在 CK+数据库和 JAFFE 数据库上取得了最先进的性能。