Wash and open oysters. Over each oyster, drop a few drops of lemon juice. Sprinkle with salt and pepper, chopped pimento, and green pepper. Stand 1/2 slice of pineapple in each shell. Drop melted butter over all. Place oysters in hot oven, 450 degrees, for 10 or 12 minutes or under broiler for 5 minutes, until pineapple is lightly brown. Serve while hot. Good with cole slaw.