High-Speed Near-IR Material Discrimination Method by Using Multidimensional Response Variables PLS Regression Analysis

Abstract

In this paper, we propose a method to discriminate multiple materials with high-speed based on the spectral reflectance properties of each material in near-infrared ray (NIR) band. A method to discriminate multiple materials with high accuracy using the same properties had already proposed. The previous method discriminates materials by using multiple binary classifiers generated by using PLS1 which is one of the Partial Least Squares (PLS) regression analysis algorithm. However, the method has a problem that it has complicated processes and takes long processing time. In order to solve this problem, we used PLS2 which is one of the PLS regression analysis algorithm just like as PLS1. In this proposed method, multiple materials can discriminate with simpler processes than the previous method by generate a multiclass classifier to discriminat e multiple materials. As a result of an experiment, multiple materials were discriminated with almost the same accuracy as the previous method, and the processing speed was improved approximately five times faster than the previous method.