Development of a Method for Pig Weight Measurement by Image Analysis.

9. 提出了一种利用图像分析估计猪体重的方法。从猪的指定投影面积与猪的活重之间的关系进行分析。323头猪的特定投影图像面积与体重呈指数关系，其中不包括耳朵和尾巴图像区域。试验猪体重为4.2 ~ 114.2 kg，由长白、杜洛克、大白和汉普郡的12种双杂交品种组成。这种关系取决于一种双杂交品种。高度差异是导致回归方程差异的主要原因，而不是长度或平均宽度差异。对指定投影面积、高度与体重的多元回归方程进行量纲分析，最接近三维，即体积。因此，如果可以间接测量猪的身高，则可以使用指定投影面积和高度的多元回归方程来估计猪的体重，精度约为*5%。利用灯在猪身上投射光线，通过图像分析测量猪肩部阴影长度，利用阴影长度与光线入射角的几何关系来估计猪的高度。对7头体重从47.6 kg到107 kg的猪进行了试验，与直接测量猪身高进行了比较。估计5头猪的身高，平均误差为*4.6%。然而，两只猪的误差在*10%以上。这就是影子在肚子上不动的原因。量肩。因此，采用光投影和图像分析技术间接估算猪的身高。该方法可以快速估计猪的体重。

9. A method was developed to estimate pig weight with image analysis. Analysis proceeded from the relationship between specified projected area of a pig from above and its live weight. Specified projected image area, which lacked ears and tail image areas, had an exponential relationship with weight for 323 pigs. The experimental pigs, weighing from 4.2 kg to 114.2 kg, consisted of 12 kinds of two-crossbreeds of Landrace, Duroc, Large White, and Hampshire. The relationship depended on a type of two-crossbreed. Height difference was the major reason of the difference in the regression equation rather than length or mean width differences. Dimensional analysis in the multiple regression equation of specified projected area and height with weight conducted that it was most close to 3 dimension, meaning volume. Hence if pig height could be measured indirectly, it will be achieved to estimate pig weight with about *5% accuracy using the multiple regression equation of specified projected area and height.Projecting light on pig with a lamp and measuring shadow length at shoulder of the pig with image analysis were attempted to estimate pig height using a geometrical relation between shadow length with light incident angle. Seven pigs, weighing from 47.6 kg to 107 kg, were experimented to compare with direct measurement of pig height. Heights for five pigs were estimated with a mean error of*4.6%. However more than *10% error were obtained for two pigs. It was the reason that shadow at belly not at. shoulder was measured. Thus, an indirect method was conducted to estimate pig height using light projection and image analysis technique. The method allows for rapid estimation of pig weight.