The front panel of the custom software.

<p>The front panel of the custom software.</p

Calibration of the spectral accuracy using the standard spectra from Krypton, Xenon, and Hg(Ar) lamp.

<p>Calibration of the spectral accuracy using the standard spectra from Krypton, Xenon, and Hg(Ar) lamp.</p

Single band images of seven non-brown trash and lint at six representative wavelengths.

<p>Single band images of seven non-brown trash and lint at six representative wavelengths.</p

The mean spectra (black solid line) and standard deviation (error bar) of seven non-brown trash and lint.

<p>The mean spectra (black solid line) and standard deviation (error bar) of seven non-brown trash and lint.</p

The schematic of the system.

<p>The schematic of the system.</p

Cotton foreign matter and cotton lint samples used in this paper.

<p>1-bark outer, 2-bark inner, 3-stem outer, 4-stem inner, 5, 6, and 7-brown leaf from DP 1050, NG5315, and PHY 339 respectively, 8, 9, and 10-bract from DP 1050, NG5315, and PHY 339 respectively, 11-hull, 12-twine, 13, 14, and 15-seed coat inner from DP 1050, NG5315, and PHY 339 respectively, 16, 17, and 18-seed coat outer from DP 1050, NG5315, and PHY 339 respectively, 19, 20, and 21-seed from DP 1050, NG5315, and PHY 339 respectively, 22-green leaf, 23-plastic bag, 24-plastic bale packaging, 25-paper, and 26, 27, and 28-cotton lint of DP 1050, NG5315, and PHY 339 respectively.</p

p-values of the Hotelling paired-test using the feature set of top three PC scores.

<p>p-values of the Hotelling paired-test using the feature set of top three PC scores.</p

PCA score plot of 15 types of cotton trash and cotton lint.

<p>(a) clusters under the top 3 PCs space, (b), (c), and (d) are projection on PC1 vs PC2, PC1 vs PC3, and PC2 vs PC3 respectively.</p

The software architecture and the state diagram of the event-driven finite state machine.

<p>The software architecture and the state diagram of the event-driven finite state machine.</p

The mean spectra (black solid line) and standard deviation (error bar) of eight brown trash.

<p>The mean spectra (black solid line) and standard deviation (error bar) of eight brown trash.</p