IDENTIFICATION OF PLASTICS AMONG NONPLASTICS IN MIXED WASTE BY REMOTE-SENSING NEAR-INFRARED IMAGING SPECTROSCOPY .1. IMAGE IMPROVEMENT AND ANALYSIS BY SINGULAR-VALUE DECOMPOSITION

A near-IR camera has been installed in an experimental setup for real- time plastic identification. Singular value decomposition (SVD) has be en used for qualitative analysis and substantial improvement of the me asured multivariate images. The obtained score plots provided spatial correlations between different pixel structures caused by sample mater ial on the one hand and image artifacts on the other. In this way, the score plots have been used as a tool to optimize the experimental set up and image quality. The improved images were offered to a new classi fication algorithm called multivariate image rank analysis, based on S VD, as described in part 2 of this series of articles, which follows i n this issue (Wienke, D.; et al. Anal. Chem. 1995, 67, 3760).