# Advancing Visible Spectroscopy through Integrated Machine Learning and Image Processing Techniques
## 2 Literature Review  
The literature review explores the growing field of spectroscopy, which is crucial in various scientific and industrial fields due to advancements in image processing and machine learning. This field is widely used in natural surface characterisation, sensor calibration, material analysis, and environmental sensing. [PERSON] et al. [1] provided a comprehensive review of field spectroscopy, emphasising its applications in characterising natural surfaces and supporting sensor calibration. Building on this, [PERSON] et al. [2] introduced a technique utilising visible light for infrared spectroscopy, highlighting its potential in material analysis and environmental sensing. [PERSON] et al. [3] presented a study on classifying bruised longan fruits using visible spectroscopy, demonstrating its industrial applications. Similarly, [PERSON] and [PERSON] [4] developed a spectrophotometric method for detecting surface bruises on apples, offering an automated quality control approach in fruit processing. [PERSON] and [PERSON] [5] discussed the impact of high-speed computers on theoretical spectroscopy, which enabled detailed analyses and facilitated collaborations in experimental research. In another domain, [PERSON] and [PERSON] [6] reviewed high-pressure sodium discharge lamps, focusing on advancements in design and their applications for outdoor lighting. [PERSON] et al. [7] investigated medium-pressure mercury discharge lamps as intense white light sources, providing insights into their atomic emission spectra and potential applications. Further extending the exploration of discharge characteristics, [PERSON] et al. [8] studied atmospheric pressure glow discharge in neon, shedding light on its behaviour in different gas mixtures. Complementing this, [PERSON] et al. [9] utilised numerical simulations to analyse homogeneous barrier discharge in helium, contributing to the understanding of plasma physics. [PERSON] and [PERSON] [10] proposed a method for sizing gold nanoparticles using UV-vis spectroscopy, offering a practical approach for nanoparticle characterisation. Finally, [PERSON] et al. [11] employed electron paramagnetic resonance spectroscopy to identify and quantify copper sites in zeolites, enhancing our understanding of their catalytic properties. [PERSON] et al. [12] utilised Raman spectroscopy to study molybdenum disulfide and trioxide, demonstrating their applications in tribological systems. [PERSON] et al. [13] highlighted the need for improved detector technologies for spectroscopic biosignature characterisation in space telescopes, underscoring the significance of advanced detection techniques. [PERSON] et al. [14] developed a method for determining Hue Saturation Value (HSV) colour features in kidney histology images, enabling automated segmentation. Similarly, [PERSON] et al. [15] investigated the Hue parameter in the HSV colour space for bitonal optical sensors, demonstrating its superior precision in sensing applications. [PERSON] et al. [16] proposed a computational framework for turbid water single-pixel imaging, which enhanced image recovery in underwater environments. This work was complemented by [PERSON] et al. [17], who discussed various aspects of spectroscopies related to pH values and the benefits of different materials and their applications. [PERSON] et al. [18] designed a refinement module to optimise the details of underwater images, achieving better visual effects and reporting the effectiveness of the proposed UIE-Convformer. In the realm of medical diagnosis, [PERSON] et al. [19] employed colour segmentation in CT scans for pneumonia detection, demonstrating the significant potential of visual computing techniques in healthcare applications. [PERSON] et al. 's [20] study on the effectiveness of the Forel-Ule Colour Index (FUI) scale in assessing natural water properties revealed its versatility in measuring water quality through ocean colour remote sensing products, handheld scales, and mobile apps. [PERSON] et al.