1. An inspection method, comprising steps of: acquiring a perspective image of an inspected object; processing the perspective image to obtain a region of interest; and automatically detecting the region of interest using a cigarette model, to determine whether the region of interest of the perspective image belongs to a cigarette; wherein before the step of automatically detecting the region of interest using a cigarette model, the method further comprises a step of setting up a cigarette model including steps of: setting up a cigarette image library; processing images in the cigarette image library to obtain respective regions of interest; extracting features of the regions of interest of the images in the cigarette image library; and training a classifier based on the extracted features to generate the cigarette model.