1. A method for evaluating a possible pallet structure comprising: providing a gray scale image comprising one or more possible lines; providing respective pixel locations in the gray scale image for an estimated upper left corner and an estimated upper right corner; calculating, using a computer, a value h based on the estimated upper left corner location and the estimated upper right corner location; estimating, using the computer, a first hole with a first rectangle having a height h, the first hole corresponding to a left opening located to the left of a possible center stringer of the possible pallet structure; estimating, using the computer, a second hole with a second rectangle having the height h, the second hole corresponding to a right opening located to the right of the possible center stringer; and estimating, using the computer, the possible center stringer with a third rectangle having the height h.