Semantic Dissimilarity Guided Locality Preserving Projections for Partial Label Dimensionality Reduction

Partial label learning (PLL) is a significant weakly supervised learning framework, where each training example corresponds to a set of candidate labels among which only one is the ground-truth label. Existing works on partial label dimensionality reduction only exploit the disambiguated labels, but overlook the available semantic dissimilarity relationship hidden in the disambiguated labeling confidence, i.e., the smaller the inner product of the labeling confidences of two instances, the less likely they have the same ground-truth label. By combining such global dissimilarity relationship with local neighborhood information, we propose a novel partial label dimensionality reduction method named SDLPP, which employs an alternating procedure including candidate label disambiguation, semantic dissimilarity generation and dimensionality reduction. The labeling confidences of candidate labels and semantic dissimilarity relationship are constantly updated through the alternating procedure, where the processes in each iteration are based on the low-dimensional data obtained in the previous iteration. After the alternating procedure, SDLPP maps the original data to a pre-specified low-dimensional feature space. Comprehensive experiments on both synthetic and real-world data sets validate that SDLPP can improve the generalization performance of different PLL algorithms, and outperform state-of-the-art partial label dimensionality reduction methods. The codes can be publicly accessible on the link https://github.com/jhjiangSEU/SDLPP.