Shape features for recognition of Pap smear cells
Shelly D. D. Goggin, Scott D. Janson · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 1996
Automated cytology relies on the use of features extracted form cell images to classify cells. This paper examines the classification capability of a number of shape features on a database of normal, abnormal and endocervical cell nuclei images. The features include the chain code, the directed Hausdorff distance, measured of the length of the radii of the cell and measures of ellipticity. The area under the receiver operating characteristic curve is used as a figure of merit. For the calculation of the directed Hausdorff distance, the images are filtered using the Sorbel gradient and erosion. The feature in the image with the largest chain code is considered to be the nucleus. The other features use images threshold at a percentage of the maximum intensity in the image. The best feature for the discrimination between normal cells and either abnormal or endocervical cells was the directed Hausdorff distance, but this feature is computationally expensive. The minimum diameter as determined by the chain code was the second best feature for recognizing abnormal cells and is less computationally expensive. Ellipticity was the second best feature for recognizing endocervical cells, which is also less computationally expensive than the directed Hausdorff distance. An optical design for the calculation of directed Hausdorff distance feature is included, which could reduce the computational expense.