探讨应用高光谱成像技术快速无损鉴别不同苹果蜡的可行性。通过对分别打食用果蜡、工业蜡和未打蜡的126个苹果样品,采用380~1 024nm范围的高光谱图像仪获取三类苹果的高光谱图像信息,采用ENVI软件处理平台提取高光谱图像中对象的漫反射光谱响应特性。从126个样品中随机取出84个样品建模,其余42个样品作为独立的验证集。对光谱数据分别采用偏最小二乘(PLS)、最小二乘支持向量机(LS-SVM)和BP神经网络等建立高光谱响应特征与食用蜡苹果、工业蜡苹果、未打蜡苹果的关系模型,比较不同建模方法的效果。结果表明:采用MSC-SPA-LS-SVM模型可以较好的区分食用果蜡、工业蜡和未打蜡的三类苹果,预测结果的正确率分别为100%,100%和92.86%。
The potential of hyperspectral imaging technology was evaluated for discriminating three types of waxed apples. Three types of apples smeared with fruit wax, with industrial wax, and not waxed respectively were imaged by a hyperspeetral imaging system with a spectral range of 308- 1 024 nm. ENVI software processing platform was used for extracting hyperspectral image object of diffuse reflection spectral response characteristics. Eighty four of 126 apple samples were selected randomly as calibra- tion set and the rest were prediction set. After different preprocess, the related mathematical models were established by using the partial least squares (PLS), the least squares support vector machine (LS-SVM) and BP neural network methods and so on. The results showed that the model of MSC-SPA-LSSVM was the best to discriminate three kinds of waxed apples with 100%, 100% and 92.86% correct prediction respectively.