摘要
针对字典对学习(DPL)方法只考虑了同类子字典的重构误差和不同类表示系数的稀疏性,没有考虑图像间的几何近邻拓扑关系的问题。通过近邻保持使得在同类近邻投影系数之间的距离较小,而不同类投影系数之间的距离大,能够有效提高字典对学习算法的分类性能,基于此提出了基于几何近邻拓扑关系的图正则化的字典对学习(GDPL)算法。在ADNI1数据集上对轻度认知功能障碍预测的实验表明,使用GDPL算法学习的编码系数作为特征预测的准确率(ACC)和ROC曲线下的面积(AUC)比使用结合生物标志作为特征预测的准确率提高了2%~6%,使用GDPL算法比DPL算法的实验结果也有提高。
Aiming at dictionary pair learning(DPL) methods only consider the reconstruction error of a sub-dictionary from the same class and the sparseness of coefficients from different classes, and do not consider the geometric neighborhood topological relationships between images. To improve the classification ability of DPL algorithms, we propose a DPL with graph regularization(GDPL) algorithm based on geometric neighborhood topological relationships. This algorithm is based on the idea that keeping the neighborhood relationship makes the distance between the neighborhood projection coefficients of the same kind small, while the distance between projection coefficients of different kinds is large. Experiments on mild cognitive impairment prediction using the ADNI1 dataset show that the coding coefficient learned from the GDPL algorithm is 2%~6% higher than that which uses the combined biomarker as feature prediction,according to accuracy(ACC) and area under curve(AUC) metrics. Moreover, the experimental result obtained using GDPL is also better than that obtained using DPL algorithm.
引文
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