TY - JOUR T1 - Unsupervised Spectral Regression Learning for Pyramid HOG AU - Qiang Li, Zhongli Peng & Xiaomei Lin JO - Journal of Fiber Bioengineering and Informatics VL - 1 SP - 117 EP - 124 PY - 2015 DA - 2015/08 SN - 8 DO - http://doi.org/10.3993/jfbi03201511 UR - https://global-sci.org/intro/article_detail/jfbi/4691.html KW - Dimensionality Reduction KW - Eigen-decomposition of Dense Matrix KW - Three-tier Pyramid HOG AB - Applying the original raw data to machine learning will bring in a poor performance, because so many features are not necessary and redundant. Extracting a small number of good features will be an important issue, and it can be solved by using dimensionality reduction techniques. However, the popular dimensionality reduction method will suffer from the eigen-decomposition of dense matrix problem which is expensive in memory and time. We adopt unsupervised (unlabeled) spectral regression method for dimensionality reduction, which well avoids the problem of dense matrix eigen-decomposition problem and can be applied on large scale data sets. Histograms of Oriented Gradients (HOG) are robust features which not only well characterize the local shape and appearance but also show a certain degree of local optical and geometry invariance. In order to characterize the local shape and appearance better, we extract a three-tier pyramid HOG descriptor vector for one sample. Then we adopt the unsupervised spectral regression method for dimensionality reduction on these descriptor vectors. Our algorithm can be applied in the library entrance guard system of university and other research fields. Several experiments on well-known face databases have shown good performance and good invariance against illumination, occlusion and local deformation, etc.

Qiang Li, Zhongli Peng and Xiaomei Lin. (2015). Unsupervised Spectral Regression Learning for Pyramid HOG. Journal of Fiber Bioengineering and Informatics. 8 (1). 117-124. doi:10.3993/jfbi03201511