1994 Volume 56 Issue 6 Pages 95-102
A method to recognize crops by image processing was developed as a basic technology to achieve a non-herbicidal, physical weeding method. Using three metric feature values related to dimension (projective area, maximum horizontal cord and maximum vertical cord), it was possible to distinguish vegetables from weeds. As a result of the comparison of growth rate between vegetables and weeds, it was assumed that the applicable periods of this method were about 30 days after transplanting for lettuce, about 35 days for cabbage, and the whole period from transplanting to harvesting for Chinese cabbage. When a neutral density filter was mounted on the camera and when luminous intensity was from 4, 000 to 60, 000lx, the errors in metric feature values were less than 4% for projective area, and less than 3% for both maximum cord.
