A quality grade classification method for fresh tea leaves based on an improved YOLOv8x-SPPCSPC-CBAM model.

Journal: Scientific reports
PMID:

Abstract

In light of the prevalent issues concerning the mechanical grading of fresh tea leaves, characterized by high damage rates and poor accuracy, as well as the limited grading precision through the integration of machine vision and machine learning (ML) algorithms, this study presents an innovative approach for classifying the quality grade of fresh tea leaves. This approach leverages an integration of image recognition and deep learning (DL) algorithm to accurately classify tea leaves' grades by identifying distinct bud and leaf combinations. The method begins by acquiring separate images of orderly scattered and randomly stacked fresh tea leaves. These images undergo data augmentation techniques, such as rotation, flipping, and contrast adjustment, to form the scattered and stacked tea leaves datasets. Subsequently, the YOLOv8x model was enhanced by Space pyramid pooling improvements (SPPCSPC) and the concentration-based attention module (CBAM). The established YOLOv8x-SPPCSPC-CBAM model is evaluated by comparing it with popular DL models, including Faster R-CNN, YOLOv5x, and YOLOv8x. The experimental findings reveal that the YOLOv8x-SPPCSPC-CBAM model delivers the most impressive results. For the scattered tea leaves, the mean average precision, precision, recall, and number of images processed per second rates of 98.2%, 95.8%, 96.7%, and 2.77, respectively, while for stacked tea leaves, they are 99.1%, 99.1%, 97.7% and 2.35, respectively. This study provides a robust framework for accurately classifying the quality grade of fresh tea leaves.

Authors

  • Xiu'yan Zhao
    College of Information Science and Engineering, Shandong Agricultural University, Taian, China.
  • Yu'xiang He
    College of Mechanical and Electronic Engineering, Shandong Agricultural University, Taian, China.
  • Hong'tao Zhang
    College of Mechanical and Electronic Engineering, Shandong Agricultural University, Taian, China.
  • Zhao'tang Ding
    Tea Research Institute, Shandong Academy of Agricultural Sciences, Jinan, China.
  • Chang'an Zhou
    College of Agronomy, College of Mechanical and Electronic Engineering, Shandong Agricultural University, Taian, Shandong, China.
  • Kai'xing Zhang
    College of Mechanical and Electronic Engineering, Shandong Agricultural University, Taian, China. kaixingzhang@139.com.