Biomedical subjects

D Jeulin

Publications and source records attributed to D Jeulin.

3 recordsLinked to original sources

PubMed2002

On the orientational analysis of planar fibre systems from digital images.

The orientational characteristics of fibres in digital images are studied. The fibres are modelled by a planar Boolean model whose typical grain is a thick (coloured) fibre. The aim is to make stereological inference on the rose of directions of the unobservable central fibres from observations made on a digital image of the thick fibres. For central fibres, the relation between the rose of directions and the point intensity, observed on a sampling line, is known. We derive, under regularity conditions, the relation between the unobservable point intensity and the scaled variogram observed on the line in a binary and a greyscale image. Using such a relation, it is possible to draw inference about the rose of directions from the scaled variogram, which is easy and quick to determine in a digital image.

Journal Article↗

PubMed2000

Image analysis of insulation mineral fibres.

We present two methods for measuring the diameter and length of man-made vitreous fibres based on the automated image analysis of scanning electron microscopy images. The fibres we want to measure are used in materials such as glass wool, which in turn are used for thermal and acoustic insulation. The measurement of the diameters and lengths of these fibres is used by the glass wool industry for quality control purposes. To obtain reliable quality estimators, the measurement of several hundred images is necessary. These measurements are usually obtained manually by operators. Manual measurements, although reliable when performed by skilled operators, are slow due to the need for the operators to rest often to retain their ability to spot faint fibres on noisy backgrounds. Moreover, the task of measuring thousands of fibres every day, even with the help of semi-automated image analysis systems, is dull and repetitive. The need for an automated procedure which could replace manual measurements is quite real. For each of the two methods that we propose to accomplish this task, we present the sample preparation, the microscope setting and the image analysis algorithms used for the segmentation of the fibres and for their measurement. We also show how a statistical analysis of the results can alleviate most measurement biases, and how we can estimate the true distribution of fibre lengths by diameter class by measuring only the lengths of the fibres visible in the field of view.

Journal Article↗

PubMed1992

Geostatistical and morphological methods applied to three-dimensional microscopy.

Three-dimensional (3-D) images of osteocyte lacunae were examined on a confocal microscope. Both geostatistical and morphological processing techniques were used to improve and to analyse them. By a geostastical approach, this study aims at improving 3-D confocal images before any further image processing. Optimized linear filters, which take account of the second-order statistics and the 3-D structure of the data, allow for the removal of imperfections such as noise and/or blur due to the axial convolution, and interpolate voxels on a face-centred cubic grid from an initial cubic grid. An application of this technique to 3-D biological images is demonstrated. In a second step, a 3-D binary image is digitized and cleaned with 3-D morphological filters. The standard 3-D measurements cannot be applied in this case, since all osteocytes cut the border of the field. For this reason a 3-D Boolean model has been adjusted, from which it is possible to derive all useful information on the repartition and the morphology of the osteocytes.

Humans↗