This paper gives out a watershed-based granular analyzing method for digital color images.The new watershed-based method which improves on the original watershed transform to some extent

can overcome the shortcoming of some conventional methods that they cannot mark the grain exactly and give a exact boundary or mark to every grain in the image.The features of grains can be acquired from these exactly marked areas and then further work can be done more easily.The paper finally applies the proposed method in some digital microscopic mineral images and obtains good results.