1. A method for detecting epithelial cells in a cell sample, comprising the steps of: a. obtaining a cell sample; b. fixing the cells of the cell sample; c. staining the cells to identify cell nuclei in the cell sample; d. illuminating the sample and obtaining an image of the sample with a microscope and a digital camera; e. compensating the image for variations in background illumination; f. analyzing the image to detect objects of interest; g. determining a focus setting for each object of interest and obtaining an image of each object of interest at its determined focus setting; h. calculating an edge that bounds each object of interest; i. calculating a set of feature values for each object of interest; and j. providing the set of feature values to a classifier that identifies epithelial cells in the objects of interest.