Hans M. Aus

Combined local color and texture analysis of stained cells

Abstract Combined color and texture techniques provide new, useful features for blood cell analysis. After scene segmentation, texture line following programs define the borders of textons, the smallest texture grains. Size, color, and shape features are then calculated for each texton. The final feature data set includes: (1) The nucleus and cytoplasm features: size and shape, measurements of the texture lines from the green TV image, average CIE-PAL color coordinates and a color code. (2) The new texton features: total number of texton pixels with a specific color code, mean texton radius, size for each color code, and texton shape factors.

Standardized color measurement in automated cytophotometry with the light micrscope

Abstract This paper discusses the need for and demonstrates the possibility of calibrating a cytophotometry system using standard colorimetry techniques. In this test, the transmittance of colored sensitometer film strips were measured from 380 to 720 nm in both a spectrophotometer and microscope TV scanning system. From the transmittance data, the CIE chromaticity coordinates of the films were calculated. The colors seen in a light microscope can be correlated to the measurements from a spectrophotometer and calibrated to the tristimulus color system, using standard measurement and analysis methods. Finally, this paper demonstrates an application of colorimetry to the cytophotometric analysis of stained blood cells.

Genormte Farbmessung und automatische Zytophotometrie in Azur B-Eosin gefärbten Präparaten

Farbe ist ein oft entscheidendes Merkmal in der visuellen Diagnose gefarbter Zeil-Praparate. Die gegenwartigen Methoden der computergestutzten Zytophotometrie sind unzureichend die in der Routine verwandten, feinen Farbunterschiede zu erfassen. Dieses Projekt beschaftigt sich mit der standardisierten, von Messystem-Charakteristika unabhangigen, Farbauswertung an Azur B — Eosin gefarbten Praparaten, um vom menschlichen, subjektiven Urteil abzukommen. Erste Ergebnisse an Kernen und Nukleolen zeigen, das die Absorptionsminima und -maxima der Komponenten der Farblosung keine geeignete Information fur die computergestutzte Analyse am gefarbten Praparat sind und das nicht von maximalen Kontrasten zwischen unterschiedlichen Zellbereichen bei festen Wellenlangen fur alle Zellen eines Praparates ausgegangen werden kann. Eine exakte, reproduzierbare, zytophotometrische Analyse der Farbeigenschaften erfordert das Erfassen des gesamten sichtbaren Spektrums in Ubereinstimmung mit dem genormten CIE-DIN-Farbsystem.

A microprocessor-controlled axiomat microscope for acquisition of cell images

Abstract This paper describes a systems approach for matching the characteristics of the microscope optics, the light sensors and associated circuits to obtain improved cell images for the subsequent computer analysis. The reported improvements eliminate the need for low-pass filtering and repeated scanning. The advantages of the required modification to both the microscope optics and the electronic circuits are demonstrated using both a TV scanner and a 3-wavelength beam splitter for simultaneous measurement of red, green and blue components of the cell images.

Die genormte Farbmessung mit dem Lichtmikroskop als Erweiterung der zytophometrischen Methodik

Es wird die Notwendigkeit diskutiert, die computergestutzte zytophotometrische Farbauswertung in der Bildanalyse medizinisch/biologischer Praparate zu standardisieren. Die beiden Moglichkeiten einer genormten Farberfassung durch Spektral- und Dreibereichsmessung und ihre Auswertung werden erlautert. An hand von Messungen mit dem Mikroskop-Photometer nach dem Spektralverfahren und Uberprufung der Meswerte mit einem Spektralphotometer wird die bisher erreichte Mesgenauigkeit demonstriert. Die Ergebnisse in dieser Arbeit zeigen, das eine genormte Farberfassung mit einem mikroskopisch/zytophotometrischen Messystem grundsatzlich moglich ist. Durch die Anwendung der international genormten Farberfassung auf gefarbte Zellen und Gewebe konnen bisher nicht oder nur teilweise geloste Fragen der computergestutzten lichtmikroskopischen Zellbilduntersuchung mit einer neuen Methodik in Angriff genommen werden.

COMPUTER COLOUR VISION: AUTOMATED SEGMENTATION OF HISTOLOGICAL TISSUE SECTIONS

Results from multifocus, true color scene segmentation algorithms are presented. The test data image base consists of digitized scenes from rat liver sections. The 3-D reconstructed cell masks correspond directly to the cells diagnosed by laboratory personnel.

Statistical evaluation of computer markers to detect leukemias

Abstract In a first clinical test, computer programs are being used to diagnose leukemias. The data set includes 20 000 cells from 120 different blood samples taken from 80 patients suffering from various hematological disorders. BMDP7M and CART statistical software test the classification power of the cell markers extracted by image processing. The feature distributions from the mononuclear cell population correlate directly to the specific leukemia. The computer methods and results presented here are part of an investigation to develop, refine and test computer aided methods in the diagnosis of blood malignancies. The data suggest the possibility of new diagnostic procedures in hematology.

On-line processing of transmission electron microscopic images

Abstract Some methods for an on-line image processing of transmission electron microscopic (TEM) images are described. The TV-scanning system is characterized by the intensity and modulation transfer function. Nonlinear noise filtering and iterative phase alignment for preprocessing the images are presented. Biomedical applications include a texture algorithm based on visual contour perception and a three dimensional reconstruction of serial sections.

A preprocessing method for the contrast enhancement of tv-scanned electron microscopic images

Abstract Preprocessing TV-scanned images in transmission electron microscopy improves the results of subsequent digital contrast enhancement. The method takes into account noise, system artifacts and the image forming modes of darkfield and brightfield.

Computer-Aided Diagnosis Of Leukemic Blood Cells

In a first clinical test, computer programs are being used to diagnose leukemias. The data collected include blood samples from patients suffering from acute myelomonocytic-, acute monocytic- and acute promyelocytic, myeloblastic, prolymphocytic, chronic lymphocytic leukemias and leukemic transformed immunocytoma. The proper differentiation of the leukemic cells is essential because the therapy depends on the type of leukemia. The algorithms analyse the fine chromatin texture and distribution in the nuclei as well as size and shape parameters from the cells and nuclei. Cells with similar nuclei from different leukemias can be distinguished from each other by analyzing the cell cytoplasm images. Recognition of these subtle differences in the cells require an image sampling rate of 15-30 pixel/micron. The results for the entire data set correlate directly to established hematological parameters and support the previously published initial training set .