Automated Counting of Rice Planthoppers in Paddy Fields Based on Image Processing

摘要

A quantitative survey of rice planthoppers in paddy ifelds is important to assess the population density and make forecasting decisions. Manual rice planthopper survey methods in paddy ifelds are time-consuming, fatiguing and tedious. This paper describes a handheld device for easily capturing planthopper images on rice stems and an automatic method for counting rice planthoppers based on image processing. The handheld device consists of a digital camera with WiFi, a smartphone and an extrendable pole. The surveyor can use the smartphone to control the camera, which is ifxed on the front of the pole by WiFi, and to photograph planthoppers on rice stems. For the counting of planthoppers on rice stems, we adopt three layers of detection that involve the following:(a) the ifrst layer of detection is an AdaBoost classiifer based on Haar features;(b) the second layer of detection is a support vector machine (SVM) classiifer based on histogram of oriented gradient (HOG) features;(c) the third layer of detection is the threshold judgment of the three features. We use this method to detect and count whiteback planthoppers (Sogatella furcifera) on rice plant images and achieve an 85.2%detection rate and a 9.6%false detection rate. The method is easy, rapid and accurate for the assessment of the population density of rice planthoppers in paddy ifelds.