1. A method of partitioning an object from an image, the method comprising: pre-setting a reference width for an object; extracting a shadow underneath the object from an image; determining a candidate region containing the object in the image based on the extracted shadow underneath the object; acquiring an imaging width of the reference width at a location of the extracted shadow underneath the object in the image; adjusting the candidate region based on the imaging width of the reference width such that the adjusted candidate region substantially completely contains the object; and partitioning the adjusted candidate region as a region containing the object from the image.