1998 Fiscal Year Final Research Report Summary
Development of a Method for Pig Weight Measurement by Image Analysis.
| Project/Area Number |
08660320
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
生物環境
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| Research Institution | Kitasato University |
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Principal Investigator |
MINAGAWA Hideo Kitasato University, Faculty of Eng.for Animal Husbandry, Assistant Professor, 獣医畜産学部, 講師 (70146520)
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| Project Period (FY) |
1996 – 1998
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| Keywords | Pig / Weight / Image Analysis / Projected Area / Height / Light Projection |
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| Research Abstract |
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.
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