Interactance spectroscopy is a relative scattering technique that is useful for measuring the internal spectral absorption characteristics of agricultural produce. However, deploying it in high-speed scanners is challenging due to the limited radiometric output of broadband white-light sources. Further complexities relate to the need to mask the incident first-surface reflected light from the detector, so more deeply-scattered interacting photons can be measured. In this paper, we describe a multispectral laser-based line-projection configuration that enables interactance measurements without requiring an obscuration. Preliminary low-throughput and high spectral resolution measurements were taken to inform the choice of laser wavelengths. Polarization cameras are used during scanning to aid in identifying regions of maximum scattering to reduce the impact of first-surface reflections. We discuss the system’s optical design and demonstrate preliminary results from the scanner.
KEYWORDS: Optical filters, Cameras, Polarization, Wave plates, RGB color model, Staring arrays, Signal to noise ratio, Polymers, Linear polarizers, Polymer thin films
Despite recent advances, customized multispectral cameras can be challenging or costly to deploy in some use cases. Complexities span electronic synchronization, multi-camera calibration, parallax and spatial coregistration, and data acquisition from multiple cameras, all of which can hamper their ease of use. This paper discusses a generalized procedure for multispectral sensing using a pixelated polarization camera and Solc stages to create multivariate optical filters. We then describe some preliminary experimental results of a fabricated filtered camera system. Finally, classification of the imagery is achieved using either shallow or deep neural networks. We also discuss the potential of using a color red, green, and blue microgrid polarization camera to detect upwards of 12 spectral channels using readily available standard off-the-shelf components.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.