????I?=?imread（‘rice.png‘）;??
????imshow（I）;??
????background?=?imopen（Istrel（‘disk‘15））;??
????figure??
????surf（double（background（1:8:end1:8:end）））zlim（[0?255]）;??
????set（gca‘ydir‘‘reverse‘）;??
????I2?=?I?-?background;??
????imshow（I2）??
????J?=?imadjust（I2）;??
????imshow（J）;??
????bw?=imbinarize（J）;??
????bw?=?bwareaopen（bw?50）;??
????imshow（bw）;??
????cc?=?bwconncomp（bw?4）;??
????cc.Numobjects;??
????grain?=?false（size（bw））;??
????grain（cc.PixelIdxList{50}）?