Deep learning for image-based large-flowered chrysanthemum cultivar recognition

Zhilan Liu,Silan Dai,Ye Tian,Jue Wang

doi:10.1186/s13007-019-0532-7

Abstract

BackgroundCultivar recognition is a basic work in flower production, research, and commercial application. Chinese large-flowered chrysanthemum (Chrysanthemum × morifolium Ramat.) is miraculous because of its high ornamental value and rich cultural deposits. However, the complicated capitulum structure, various floret types and numerous cultivars hinder chrysanthemum cultivar recognition. Here, we explore how deep learning method can be applied to chrysanthemum cultivar recognition.ResultsWe propose deep learning models with two networks VGG16 and ResNet50 to recognize large-flowered chrysanthemum. Dataset A comprising 14,000 images for 103 cultivars, and dataset B comprising 197 images from different years were collected. Dataset A was used to train the networks and determine the calibration accuracy (Top-5 rate of above 98%), and dataset B was used to evaluate the model generalization performance (Top-5 rate of above 78%). Moreover, gradient-weighted class activation mapping (Grad-CAM) visualization and feature clustering analysis were used to explore how the deep learning model recognizes chrysanthemum cultivars.ConclusionDeep learning method applied to cultivar recognition is a breakthrough in horticultural science with the advantages of strong recognition performance and high recognition speed. Inflorescence edge areas, disc floret areas, inflorescence colour and inflorescence shape may well be the key factors in model decision-making process, which are also critical in human decision-making.

Highlights

Cultivar recognition is a basic work in flower production, research, and commercial application
Chrysanthemum × morifolium Ramat., which originated in China, has high ornamental and commercial value in the floriculture industry around the world [1,2,3], and its major production areas cover China, Japan, the Netherlands and South Korea [4]
Image dataset A Cultivar selection and plantation The experimental material is traditional Chinese largeflowered chrysanthemum cultivar group. 103 cultivars were selected, and some of them were similar in terms of morphology (Fig. 2)

Summary

Introduction

Cultivar recognition is a basic work in flower production, research, and commercial application. Chinese large-flowered chrysanthemum (Chrysanthemum × morifolium Ramat.) is miraculous because of its high ornamental value and rich cultural deposits. Chrysanthemum × morifolium Ramat., which originated in China, has high ornamental and commercial value in the floriculture industry around the world [1,2,3], and its major production areas cover China, Japan, the Netherlands and South Korea [4]. The growing number of new chrysanthemum cultivars bred around the world has made it harder to recognize, even if professional researchers may confuse chrysanthemum cultivar, In previous studies, the traditional morphological method, the comprehensive mathematical statistics method and molecular markers were used to solve the large-flowered chrysanthemum recognition problem. Molecular markers have the potential to recognize cultivars with similar morphological features [17], but required laboratory testing over long periods of at least half a day. The rapid recognition of large-flowered chrysanthemums is difficult to achieve

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Discussion

Conclusion