An active contour algorithm for prediction of loin eye area (LEA) in the transectional Autofom images has been developed and implemented. The results of 75 carcasses measured at Hatfield Quality Meats indicate a standard error below 1 square inch by combining the algorithm with the current 127 Autofom features. Future studies of more carcasses, optimization of the algorithm, and better energy functions are expected to improve the results. With a speed optimization of the algorithm, there is potential for using the Autofom for on-line sorting of loins based upon loin muscle area