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Biomedical subjects

J W Bacus

Publications and source records attributed to J W Bacus.

39 records · Page 3Linked to original sources

Error measures for objective assessment of scene segmentation algorithms.

Scene segmentation is an important element in pattern recognition problems. Previous efforts to evaluate and compare scene segmentation procedures have been largely subjective. Quantitative error measures would facilitate objective comparison of scene segmentation algorithms. A theoretical discussion leading to a new generalized quantitative error measure, G2, based on comparison of both pixel class proportions and spatial distributions of "true" and test segmentations, is presented. This error measure was tested on 14 manual segmentations and 40 gynecologic cytology specimens segmented with five different scene segmentation techniques. Results indicate that G2 seems to have the desirable properties of correlation with human observation, categorization of error allowing for weighting, invariance with picture size and ease of computation necessary for a useful scene segmentation error measure.

Autoanalysis↗

Studies on Papanicolaou staining. I. Visible-light spectra of stained cervical cells.

This paper presents visible-light absorbance spectra of the nuclei and cytoplasms of ten types of cervical cells stained by the Papanicolaou technique, together with tables summarizing the data. It is concluded that for automated image processing of Papanicolaou smears the most suitable wavelengths are 531 nm to maximize the contrast of cell against background and a wavelength in the range 560 nm to 605 nm (with a mean at 575 nm) to maximize the contrast of the nucleus against the cytoplasm.

Carcinoma in Situ↗

Studies on Papanicolaou staining. II. Quantitation of dye components bound to cervical cells.

Dye binding to Papanicolaou-stained cervical cells was quantitated with a spectral subtraction technique. It was shown that of the dye components of Papanicolaou stains only aluminum hematein, orange G, light green SF and eosin Y are bound to cervical cells and that their chromophores do not interact. Bismarck brown Y was not bound to cervical cells, which confirms the subjective findings of previous authors, and so it should be omitted. No evidence of substrate-related variations in dye polymerization was found. The proportions of the four dyes were found to vary considerably from substrate to substrate. Spectra are presented of (1) solutions of the component dyes of the Papanicolaou stain, and (2) cervical cells stained with these individual component dyes, for comparison with the full Papanicolaou technique.

Cell Nucleus↗