Abstract
A automated noncontact weight system for pigs consisted of a CCD-type video camera and 10 photo sensors connected to a computer. In the experiment 20 pigs(Large Yorkshire $\times$ Landrace breed) weighing from 95kg to 115kg were used. Pig's original image data was transformed to a binary image an image excluding head and tail portion from the whole binary image and the area of pig was calculated. Then pig's volume was calculated by multiplying the area by the body hight measured with photo sensors. The correlation equation between the above volume(x) and pig's weight was y=0.0007 x -9.2152($R^2$=0.9965) Performance of a automated noncontact weighing system for pigs was tested with this equation. The results showed $\pm$0.65kg average error and 1.63kg maximum error. It was concluded that performance of a automated noncontact weighing system is excellent.