Biomedical subjects

H Jeanty

Publications and source records attributed to H Jeanty.

3 recordsLinked to original sources

PubMed1989

The use of local entropy measures in edge detection for cytological image analysis.

Accurate edge detection is a fundamental problem in the areas of image processing and pattern recognition/classification. The lack of effective edge detection methods has slowed the application of image processing to many areas, in particular diagnostic cytology, and is a major factor in the lack of acceptance of image processing in service orientated pathology. In this paper, we present a two-step procedure which detects edges. Since most images are corrupted by noise and often contain artefacts, the first step is to clean up the image. Our approach is to use a median filter to reduce noise and background artefacts. The second operation is to locate image pixels which are 'information rich' by using local statistics. This step locates the regions of the image most likely to contain edges. The application of a threshold can then pin-point those pixels forming the edge of structures of interest. The procedure has been tested on routine cytologic specimens.

Algorithms↗

PubMed1988

Septal thickness in human lungs assessed by computerized interactive morphometry.

We have studied the feasibility of using interactive computerized morphometric methods for the quantitation of septal thickness in the lung with the goal of introducing objective criteria for the diagnosis and grading of pulmonary fibrosis and edema. After reviewing available methods, we have decided in favor of linear intercept measurements of septal profiles which are limited to the tissue and therefore not affected by the level of lung inflation. Our method consisted in generating a graphic overlay of parallel lines over a real time video display of lung tissue. We had the options of measuring either uniformly oriented (random) or orthogonal intercepts. Randomly oriented intercepts (i.e., those with incidence angles ranging between 0 and 90 degrees) resulted in poor statistics because of excessive scattering of primary data; we resolved this difficulty by limiting the incident angle to the range of +/- 45 degrees from the normal to the septum at the point of sampling. This results in marked increase in consistency and reproducibility of the results with fewer measurements. Alternatively, we used intercepts measured over a line generated perpendicularly to the septal axis which approaches orthogonal thickness measurements. We found that both approaches yield acceptable results after as little as 50 measurements.

Computer Simulation↗

PubMed1987

Computerized interactive morphometry in pathology: current instrumentation and methods.

This review is concerned with the current applications of interactive computerized morphometry for diagnostic applications. "Interactive" differs from fully automatic procedures in that the essential function of cell recognition is performed by a trained observer, assisted by a computerized instrument that performs all desirable measurement and processing tasks. This article describes the instrumental needs (video systems, computer, and specialized hardware) and interactive peripherals, in particular, high-resolution touch screens for most common and currently useful video analysis tasks. The authors describe a number of general instrumental procedures with widespread applications (point counting, tracing of contours, graphic standards of size and length, shape analysis, automatic edge detection). Diagnostic procedures are based on the generation of multiple data followed by either multivariate statistical analysis that allows diagnosis of individual cases or hierarchical algorithms. The best current application is the objective study of controversial or difficult cases; there is a possibility that in the future interactive computerized morphometry may become useful for the mass screening of cytologic specimens.

Analog-Digital Conversion↗