Zhou Tongtong, Hu Dong, Qiu Dekai, Yu Shengqi, Huang Yuping, Sun Zhizhong, Sun Xiaolin, Zhou Guoquan, Sun Tong, Peng Hehuan
College of Optical Mechanical and Electrical Engineering, Zhejiang A&F University, Hangzhou 311300, China.
College of Mechanical and Electronic Engineering, Nanjing Forestry University, Nanjing 210037, China.
Foods. 2023 Apr 25;12(9):1783. doi: 10.3390/foods12091783.
Spatial-frequency domain imaging (SFDI) has been developed as an emerging modality for detecting early-stage bruises of fruits, such as apples, due to its unique advantage of a depth-resolved imaging feature. This paper presents theoretical and experimental analyses to determine the light penetration depth in apple tissues under spatially modulated illumination. Simulation and practical experiments were then carried out to explore the maximum light penetration depths in 'Golden Delicious' apples. Then, apple experiments for early-stage bruise detection using the estimated reduced scattering coefficient mapping were conducted to validate the results of light penetration depths. The results showed that the simulations produced comparable or a little larger light penetration depth in apple tissues (2.2 mm) than the practical experiment (1.8 mm or ~2.3 mm). Apple peel further decreased the light penetration depth due to the high absorption properties of pigment contents. Apple bruises located beneath the surface peel with the depth of about 0-1.2 mm could be effectively detected by the SFDI technique. This study, to our knowledge, made the first effort to investigate the light penetration depth in apple tissues by SFDI, which would provide useful information for enhanced detection of early-stage apple bruising by selecting the appropriate spatial frequency.
空间频域成像（SFDI）作为一种新兴的检测苹果等水果早期瘀伤的技术已得到发展，这是由于其具有深度分辨成像特征这一独特优势。本文进行了理论和实验分析，以确定在空间调制照明下苹果组织中的光穿透深度。随后进行了模拟和实际实验，以探究“金冠”苹果中的最大光穿透深度。然后，利用估计的约化散射系数映射进行了苹果早期瘀伤检测实验，以验证光穿透深度的结果。结果表明，模拟得出的苹果组织光穿透深度（约2.2毫米）与实际实验结果（约1.8毫米或约2.3毫米）相当或略大。由于色素成分的高吸收特性，苹果皮进一步降低了光穿透深度。SFDI技术能够有效检测位于表面果皮下方深度约为0 - 1.2毫米的苹果瘀伤。据我们所知，本研究首次尝试通过SFDI研究苹果组织中的光穿透深度，这将为通过选择合适的空间频率增强早期苹果瘀伤检测提供有用信息。
Zotero 插件
