A generic platform for hyperspectral mapping of wood

Abstract

Sustainable use is essential to guarantee future availability of wood. Structural and chemical mapping can contribute to fit-for-purpose usage, as accurate and detailed knowledge of the material enables guided utilization and optimal performance of wood. The platform presented in this paper, illustrated on poplar disks for early selection, collects data in the NIR, visual and X-ray spectrum in maximum 30 min per wood disk. Flatbed scanning proves to be a cheap and fast technique to evaluate basic physical properties such as cross-sectional area and wood density. X-ray CT scanning is used for density mapping adding information on density variation between and within disks. Chemometric modeling of infrared spectra is used to map density, tension wood and lignin content. X-ray- and NIR-based density mapping showed good correlation, although NIR-based maps do not show the same level of detail as X-ray images do due to lower resolution. Results of NIR-based hyperspectral mapping illustrate that tension wood zones were denser and contained less lignin which corresponds with the existence of the G-layer described in the literature. In all, the combination of high-end tools together with simple tools such as flatbed scanning allows for high-throughput and high-resolution quantitative mapping of some of the main properties of poplar wood. Furthermore, infrared scanning can be used to map density, tension wood and chemistry without the need for more complex, expensive and/or time-consuming methods, yet with less accuracy and lower resolution, thus being applicable as single tool for breeding selection

Non-Destructive Evaluation Techniques and What They Tell Us about Wood Property Variation

“…An example is the dual energy approach (scanning at two energies which improves differentiating between features, in this case water in wood) recently showcased for moisture mapping of wood [337]. Finally, multi-spectral and multi-modal workflows (SilviScan and DiscBot are examples) either by combination of several different cutting-edge equipment [338] for a combination of optical, X-ray, and NIR imaging) or by combination in a single machine (Laforce et al [339] combining X-ray, CT, and X-ray fluorescence) are currently being developed. NDE tools have presented new opportunities for tree breeding programs.…”

Quantitative prediction of moisture content distribution in acetylated wood using near-infrared hyperspectral imaging

“…In this regard, hyperspectral near-infrared (NIR) imaging is an appropriate method to study structural and chemical changes within the wood [10][11][12]. The NIR images are three-way datasets, where two dimensions render the spatial mapping of the chemical analytes, while the third dimension contains spectral variables.…”

Comparative Performance of NIR-Hyperspectral Imaging Systems

“…Similarly, wood-related NIR-and SWIR-HSI research has been increasingly reported in the literature, where cameras have been used to examine various spectral and spatial properties and variations of wood materials. Applications include the estimation of physical and mechanical properties of radial strips [11][12][13][14][15] and lumber [16][17][18] as well as the detection of compression wood [19,20], tension wood [21] and resin defects [22]. A common area of research has been the estimation of wood moisture content [23][24][25], and associated research includes an investigation of changes in the spatial distribution of water when wood is dried [20].…”