基于双目视觉及Mask RCNN的牛体尺无接触测量

Non-contact measurement of bovine body size based on binocular vision and Mask RCNN

为了解决传统牛体尺参数测量中存在测量难度大、牛应激反应强等问题,试验采用Mask RCNN算法结合牛体尺测点识别的方法,基于双目视觉原理测定牛体尺参数,并利用实验室8个黄牛模型和内蒙古乌兰察布市察哈尔右翼中旗某牧场7头西门达尔牛对建立的牛体尺参数无接触测量系统进行验证,并与人工测量值进行比较分析。结果表明:利用Mask RCNN算法对牛图像进行分割并提取牛轮廓曲线,极大的缩短了轮廓提取的时间并且更适用于复杂背景;划分牛体轮廓曲线区域,利用最大曲率等方法可以准确的识别牛体尺测点;利用双目视觉原理将牛体尺测点像素坐标转化为空间3维坐标,利用欧氏距离计算牛体尺参数。实验室系统验证结果与人工测量值比较,其体长、体高、体斜长的平均相对误差分别为1.41%、0.92%和1.37%;某牧场实地系统验证结果与人工测量值比较,其体长、体高、体斜长的平均相对误差分别为6.09%、5.78%、6.85%,均满足测量需求。说明Mask RCNN算法能够较好地在复杂背景中提取牛轮廓,牛体尺测点识别准确,能够在饲养过程中实现牛体尺参数的无接触测量。

In order to solve the problems of traditional measurement of cattle body size parameters, such as the difficulty in measurement and strong stress response of cattle, the method of identifying the measurement points of cattle body size, based on the principle of binocular vision was used in the experiment. The results showed that using Mask RCNN algorithm to segment the cattle image and extract the cattle contour curve can greatly shorten the extraction time and wasmore suitable for the complex background. By dividing the contour curve region of the bovine body, the measuring points of the bovine body measurement can be identified accurately by means of the maximum curvature.Based on the principle of binocular vision,the pixel coordinates of the measuring pointscan be transformed into 3 d coordinates, and the Euclidean distance can beused to calculate the cattle body size parameters. The results of laboratory system verification are compared with those of manual measurement, the average relative errors of length, height and slant length are 1.41%, 0.92% and 1.37%, the result of the pasture system verification are compared with those of manual measurement, the average relative errors of lenght, height and slant length are 6.09%, 5.78% and 6.85%, all meets the needs of sequencing. It indicated that the Mask RCNN algorithm can better extract the contour of the cattle in the complex background, identifythe measurement point accurately, and realize thenon-contact measurement of the cattle body sizeparameters in the breeding process.