自然环境中的红色番茄图像识别方法研究

Research on recognition methods for red tomato image in the natural environment

针对机器人采摘过程中因对自然环境中的光照变化、土壤及枝叶等背景和果实间重叠等实际情况造成的红色番茄识别不准确的难题,提出了一种基于圆拟合算法的番茄图像识别方法。使用照相机采集番茄图像,在Matlab软件平台中选择三原色(red,green,blue,RGB)彩色空间进行实验;利用红-绿(red-green,R-G)色差分量对番茄图像进行预处理,然后分别采用边缘检测算法、阈值分割和分水岭分割方法对果实目标和背景进行分割,最终选用阈值分割中的最大类间方差法进行图像分割,并基于反向传播人工神经网络(back propagation-artificial neural network,BP-ANN)和圆拟合算法进行番茄果实的识别,最终得到红色番茄果实的轮廓、质心和半径,即定位果实目标。对红色番茄图像的识别结果进行统计,圆拟合算法的识别率高达90.07%。此算法不仅对单个果实的识别率高,还较好地解决了复杂环境下多个果实重叠的识别问题,为后续的机器人采摘工作打下了良好的理论基础。

In view of actual situations such as light change,soil,branch and leaf background and fruit overlap in the natural environment,which causing the problem of red tomato recognition during the robotic picking process was not accurate,a tomato image recognition method based on circle fitting algorithm was proposed.We collected the images of tomato by camera,used the red,green,blue(RGB)color space based Matlab as simulation experiment,and preprocessed the tomato images with red-green(R-G)color component.Then,edge detection algorithm,threshold segmentation and watershed segmentation methods were adopted to segment tomato target and the background,respectively.The Otsu segmentation method of threshold segmentation was adopted,which was best to segment target.We used the back propagation-artificial neural network(BP-ANN)and circle fitting algorithm to recognize the tomato fruit.Finally,the contour,centroid and radius of the red tomato were obtained.The results of red tomato images were statistically analyzed,and the recognition rate of circle fitting algorithm was as high as 90.07%.This algorithm not only has a high recognition rate for single fruit,but also solves the problem of multiple fruit overlapping in a complex environment,which lays a good foundation for the following robotic picking work.