A Maturity Detection Method for Hemerocallis Citrina Baroni Based on Lightweight and Attention Mechanism

Hemerocallis citrina Baroni with different maturity levels has different uses for food and medicine and has different economic benefits and sales value. However, the growth speed of Hemerocallis citrina Baroni is fast, the harvesting cycle is short, and the maturity identification is completely dependent on experience, so the harvesting efficiency is low, the dependence on manual labor is large, and the identification standard is not uniform. In this paper, we propose a GCB YOLOv7 Hemerocallis citrina Baroni maturity detection method based on a lightweight neural network and attention mechanism. First, lightweight Ghost convolution is introduced to reduce the difficulty of feature extraction and decrease the number of computations and parameters of the model. Second, between the feature extraction backbone network and the feature fusion network, the CBAM mechanism is added to perform the feature extraction independently in the channel and spatial dimensions, which improves the tendency of the feature extraction and enhances the expressive ability of the model. Last, in the feature fusion network, Bi FPN is used instead of the concatenate feature fusion method, which increases the information fusion channels while decreasing the number of edge nodes and realizing cross-channel information fusion. The experimental results show that the improved GCB YOLOv7 algorithm reduces the number of parameters and floating-point operations by about 2.03 million and 7.3 G, respectively. The training time is reduced by about 0.122 h, and the model volume is compressed from 74.8 M to 70.8 M. In addition, the average precision is improved from 91.3% to 92.2%, mAP@0.5 and mAP@0.5:0.95 are improved by about 1.38% and 0.20%, respectively, and the detection efficiency reaches 10 ms/frame, which meets the real-time performance requirements. It can be seen that the improved GCB YOLOv7 algorithm is not only lightweight but also effectively improves detection precision.