1. A method of classifying, with a computer processor, at least one feature of each of a plurality of cells from a low contrast, digital image representing the plurality of cells, the method comprising: generating a contrast-enhanced image by filtering the low contrast, digital image with a high-pass filter; smoothing the contrast-enhanced image with a first low-pass filter; generating a background image from the low contrast, digital image; subtracting the background image from the smoothed, contrast-enhanced image to generate an analysis image; and identifying the at least one feature in the analysis image.