# Snapshot-Based Multispectral Imaging for Heat Stress Detection in Southern-Type Garlic
###### Abstract
For instance, experiments were carried out in 2021 to detect high-temperature stress in ginseng, while in 2022, fluorescent hyperspectral imaging was employed to detect high-temperature stress in ginseng and strawberries [26; 27; 28]. Considering the projected rise in temperature due to global warming, understanding the effect of high-temperature stress on garlic crop growth and developing methods to detect and mitigate it are crucial. Traditional methods for assessing plant stress rely on time-consuming, subjective visual observations or invasive techniques that often require destructive sampling. In recent years, there has been increasing interest in non-invasive, real-time monitoring techniques that provide accurate and objective assessments of plant stress [29; 30]. Hyperspectral and multispectral imaging are non-destructive methods used to obtain images at numerous wavelengths without damaging the crop [26; 27; 28]. In this study, we utilize multispectral analysis and a multispectral snapshot camera to detect high-temperature stress in southern-type garlic. The snapshot-based approach, along with line-scanning and snap-scanning methods, enables the acquisition of hyperspectral and multispectral images using a single camera. The line-scanning method involves scanning as the camera or the object moves, while the snap-scanning method acquires data by scanning inside the camera without moving it or the object. The snapshot method captures data of multiple wavelengths simultaneously, eliminating the need for scanning time and enabling faster data acquisition, albeit with a relatively limited range of obtainable wavelengths compared to the scanning methods [31; 32; 33]. Among these techniques, snapshot-based hyperspectral imaging and multispectral imaging have emerged as promising tools for non-destructive plant stress diagnosis, allowing for the simultaneous capture and analysis of visible and near-infrared spectra [31; 32; 33]. Hyperspectral imaging and multispectral imaging combine spectroscopy principles with digital imaging, facilitating the acquisition of spectral information across a wide range of wavelengths. By analyzing the unique spectral signatures of plant tissues, these imaging techniques enable the detection of subtle changes associated with stress-induced physiological responses. They have been successfully applied in various agricultural applications, including assessing nutrient deficiencies, disease detection, and stress monitoring in crops [26; 27; 28; 30]. In particular, the VIS/NIR wavelengths were chosen to capture the absorption characteristics of pigments, such as chlorophyll, that are vital for photosynthesis, changes in plant cellular structures, water content, and leaf internal composition and indicative of plant health. These wavelengths are known to be sensitive to changes in pigment concentrations and can provide insights into the plant's photosynthetic activity and stress-induced alterations. In addition, these wavelengths also allow us to assess stress-related changes in cellular structures, such as leaf thickness and internal scattering, which can affect the spectral response. In the context of garlic crop management, the application of hyperspectral imaging and multispectral imaging holds great potential for evaluating high-temperature stress-induced physiological changes. By capturing and analyzing the spectral response of garlic plants under different temperature regimes, it becomes possible to identify specific spectral features indicative of stress conditions. These features can serve as indicators or biomarkers for evaluating the severity and extent of high-temperature stress on garlic crop growth. Despite the potential of hyperspectral imaging and multispectral imaging, limited research has focused on their utilization for evaluating high-temperature stress in garlic crops. Most studies have primarily targeted other crops or different stress conditions.