Computer Image Processing System Research Articles

Computer image analysis of abrasion debris

The shape, size and distribution of debris produced in a dry sand rubber wheel abrasion test were measured using a computer image-processing system and important information about the formation of debris was obtained. The new methods and the targets for describing debris are proposed. In terms of these parameters, the process of abrasive wear can be analysed.

Dust emission phenomena of cometary analogues

Experiments with cometary analogues are reported, which were performed at DLR - Köln in a small vacuum chamber and in the Space Simulator. The results apply to the emission processes of ice-dust grains from the surface of mineral-ice mixtures during insolation. The emission phenomena were observed with CCD-video-cameras. The camera used at the small chamber was equipped with a magnifying (10x) macro-lens. The magnified pictures show that the ice-dust agglomerates carry tiny ice particles on their surfaces. These may play the role of interlinking bonds between one grain and its neighbors. In the enlarged view it can be seen that the ice-dust grains do not erupt with high velocity out of the surface. The upstreaming gas jet originating from the sublimation of the volatile components first erodes the interlinking bonds between the particles. When the drag force exerted on the particles exceeds the force of gravity, the particles lift off. In most of the observed cases this initial lift off velocity is very small e.g. a few cm/s. During a comet-simulation experiment in the Space-Simulator in November 1989 the trajectories of emitted dust particles were recorded for the first time with a high speed shutter video system 60 cm from the model comet. The video tapes were evaluated with a computerized image processing system. Unique insights in the gas-dust-interaction immediately at and above the insolated icy body were obtained. The trajectories differ markedly in all cases from the the ballistic parabolas calculated from the measured starting conditions: elevation angle and speed. The trajectory is mainly dominated by the momentum transfer from the gas jet to the dust particles. Many of the particles have millimeter sizes. The observed velocities at the end of the visible trajectory are in the order of a few meters per second.

画像解析システムを用いた塩酸胃粘膜損傷モデルの判定法

Oral administration of HCl (0.2 N, 0.4 N, 0.6 N, 0.8 N) solution produced congestive or hemorrhagic gastric mucosal lesions in rats. Lesion areas were differentiated into two areas (i.e., brown area and black area) macroscopically. Then, fine observations were performed on two areas using a computer image processing system (CIPS) and histological techniques. Cell necrosis from the mucosal surface to the middle mucosal layer were observed in the brown area, and gastric mucosal necrosis that reached to a deeper layer were observed in the black area. These results indicate that histological degree of lesion may be reflected in the macroscopic changes. Concerning the concentration of HCl, over 0.4 N HCl solution induced mucosal lesions, but HCl solution (0.4 N HCl) only produced a brown area. Maximum changes in the mucosal surface were observed at 30 min to 1 hr by 0.6 N HCl and at 15 to 30 min by 0.8 N HCl. Therefore, the best condition for evaluating the preventive effects of anti-ulcer agents is 30 min after treatment by 0.6 N HCl solution and 15-30 min after treatment by 0.8 N HCl solution. These results suggest that this technique may provide both quantitative and qualitative information on histological changes.

走査電子顕微鏡による疲労き裂進展挙動の動的直接観察と画像処理技術の開発

The computer image processing system incorporated into the specially designed servo-hydraulic fatigue loading facilities operating in a scanning electron microscope (SEM) has been developed. The image processing system developed is composed of a micro-computer (NEC PC9801, memory capacity is 4 Mbytes) and a high-speed direct memory access type A/D converter (ELMEC EC-2390). The secondary electron signal of SEM was directly transferred to the memory of micro-computer through the converter at a digitizing rate of 5 to 50μsec per point. By using this system, the sampling of successive five flames of SEM image data during fatigue loading of 0.1Hz become possible.Direct, real time observations of fatigue crack growth behavior under both constant amplitude and repeated two-step loadings were made. Both the crack profile and the contours of fine magnesium oxide particles, which were scattered on the specimen surface as location markers, were extracted from the original SEM image data by using the image processing technique, and this processed image data was used in quantitative analyses of crack opening displacement, deformation behavior near the crack tip and crack growth increment.

Marked and variable inhibition by chemical fixation of cytochrome oxidase and succinate dehydrogenase in single motoneurons.

The effect of tissue fixation on succinate dehydrogenase and cytochrome oxidase activity in single motoneurons of the rat was demonstrated using a computer image processing system. Inhibition of enzyme activity by chemical fixation was variable, with some motoneurons being affected more than others. It was concluded that quantification of enzymatic activity in chemically fixed tissue provides an imprecise estimate of enzyme activities found in fresh-frozen tissues.

Study of morphological distribution of defects in GaAs wafers by infrared digital image processing

A new method is applied to characterize the defects in GaAs material (e. g. the absorption of EL2 centres). The method consists of transmitting a laser beam (λ=1.1–1.5 μm) through the GaAs wafer of 4–8 mm thickness and 50 mm diameter. The image is received by the TOSHIBA 8844, camera and entered into the DATASUD computer image processing system. This image is displayed on a monitor permitting to observe the inhomogeneity (like cross, cells and volutes) of the EL2 and dislocation defects. This paper will introduce a specific image processing software for GaAs material, called ZHIMAG (ZHang IMAGe) and its application to GaAs wafer. The software can be also applied to any other types of image processing.

The Measurement of Gastric Mucus Using a Computer Image Processing System

The measurement of gastric mucus, and the effects of aspirin and some antiulcer drugs on the content or components of gastric mucus were investigated in normal rats by using a newly devised computer image processing system. The present method enabled us to separate mucus components into PAS positive mucus (PAS+), and AB positive mucus (AB+), and to measure the amount of each mucus. Aspirin induced significant decreases in both PAS+ and AB+, teprenone increased the total amount of gastric mucus (PAS+ plus AB+), secretin tended to increase AB+, and cimetidine and omeprazole caused no remarkable changes on mucus secretion. These changes in gastric mucus could be observed on both microscopic observation and with the computer image processing system. The results indicate that the computer image processing system is very useful for the measurement of gastric mucus.

Behavior of Percolation Clusters in Sintered Mixture of Niobium and Alumina

Percolative behavior of clusters in sintered mixtures of Nb and Al2O3 was observed. The percolation transition occurs when the volume fraction f of Nb is about 0.16 in agreement with the continuum percolation theory. Statistical distributions of the clusters with respect to size and perimeter were also measured with an image processing computer system. After the percolation transition, the cluster distribution becomes broad and discrete, indicating a process of coupling between clusters.

Real time computer tracking of free-swimming and tethered rotating cells

A computerized image processing system has been developed that tracks individual free-swimming cells and rotating bacterial cell bodies tethered by their flagella in real time. Free-swimming bacteria of Rhodobacter sphaeroides, Rhodospirullum rubrum, and Salmonella typhimurium have been tracked swimming at speeds from 0 to over 120 μm s −1. A high level of discrimination is exerted against noncellular objects, allowing analysis of stopped as well as moving cells. This enabled detection of both speed and qualitative change in the swimming patterns of R. sphaeroides WS8 upon tactic stimulation. Comparison with darkfield microscopy indicated that the two techniques were in substantial agreement. The unidirectional rotation of cells of R. sphaeroides WS8 could be detected when the cells were either parallel to the microscope slide or end on. Frequencies of rotation of up to 10 Hz were monitored before image blurring became a problem. True rods would be easier to analyze at higher speeds of rotation. Although developed for photosynthetic bacteria, a wide range of bacteria, eucaryotic organisms, and subcellular organelles could be tracked with this system. Minor modifications to the software allow customization to different types of motility analysis.

Local cerebral glucose utilization in the Ammon's horn and dentate gyrus of the rat brain.

The local cerebral glucose utilization (LCGU) was measured in different regions and layers of the Ammon's horn and dentate gyrus in the conscious rat. The LCGU was determined by quantitative [14C]2-deoxyglucose autoradiography using a computerized image processing system. In the hippocampus, the various regions and layers exhibited different glucose consumptions, the lowest values being found in the alveus and the highest ones in the lacunosum-molecular layers of the sectors of the Ammon's horn and the molecular layer of the dentate gyrus' external limb. Additionally, in many layers, the LCGU values of the left hemispheres were found to be higher compared with the right hemispheres. The analysis of LCGU changes in rostrocaudal direction revealed, that in sector 1 of Ammon's horn and in the dentate gyrus the glucose consumption decreased from rostral to caudal levels, whereas in sector 3 of Ammon's horn an increase was found.

Quantitative autoradiography of transmitter binding sites with an image analyzer

A computerized image processing system for quantitative receptor autoradiography on tritium-sensitive film is described. The method implements an image analyzer ( IBAS 1 + 2) for the acquisition of an image which is evaluated with respect to the regional distribution of binding site densities by a small computer which is connected to a digitizer. Several methodological problems must be considered when using tritium-labelled compounds and an image analyzer. The use of tissue standards and shading procedures, the improvement of signal-to-noise ratio, the calibration of the system which establishes the non-linear relation between grey values and concentration of radioactivity, the contrast enhancement and the quenching problem are discussed. This method permits a quick and precise quantitative analysis of binding site distribution in receptor autoradiography.

GLUCOSE UTILIZATION IN ADULT RAT BRAIN FOLLOING NEONATAL TREATMENT WITH MORPHINE, A QUANTITATIVE AUTORADIOGRAPHIC STUDY

Previous experimental evidence has shown that neonatal exposure to morphine has lasting effects on pain thresholds and the density of opiate receptor sites in several brain regions (Handelmann & Quirion, European J Pharmac. , in press). In order to more clearly define the functional correlates of the altered distribution of opiate receptors, we chose the autoradiographic 14C Deoxyglucose method for measuring in vivo glucose utilization rates in brain tissue (Sokoloff et al., J Neurochemistry 28:897-916, 1977). Newborn albino rats were injected s.c. with lug morphine sulfate in 5ul phosphate buffered saline each day on postnatal days 1 through 7. The deoxyglucose experiments were performed after the rats were 3 months of age. The frozen brains were sectioned 20microns thick and used to produce images on Xray film. Optical densities were obtained using a computerized image processing system. Glucose utilization rates were altered in several brain regions when compared to control values. Notably the reduced glucose metabolic rate found in the dentate gyrus of the hippocampus correlated well with the altered density of opiate receptors in that structure.

Automatic fringe analysis with a computer image-processing system

The application of a general-purpose image-processing computer system to automatic fringe analysis is presented. Three areas of application have been examined where the use of a system based on a random access frame store has enabled a processing algorithm to be developed to suit a specific problem. Furthermore, it has enabled automatic analysis to be performed with complex and noisy data. The applications considered are strain measurement by speckle interferometry, position location in three axes, and fault detection in holographic nondestructive testing. A brief description of each problem is presented, followed by a description of the processing algorithm, results, and timings.

A minicomputer system for image processing of electron micrographs

This paper describes how a PDP 11/34A computer system was set up to handle research problems in computer image processing of electron micrographs. This system is referred to as CIPRES, for Computer Image Processing and Reconstruction System (pronounced the same as cypress, the name of an evergreen tree). The RSX-11M operating system is used. Various execution speeds are given. For instance, a disk-based fast Fourier transform or FFT (complex to complex, 128 X 128 pixels) runs in three minutes. This report may be useful to anyone wishing to set up a similar computer system.

Three-dimensional echocardiography for spatial visualization and volume calculation of cardiac structures.

A new computerized image processing system was developed and applied clinically for three-dimensional visualization and volume calculation of cardiac structures, which were recorded in more than seven original two-dimensional echocardiograms in parallel planes. Three-dimensional display of this series of original two-dimensional echocardiograms was performed automatically using an overlaid display with different gray levels designating depths. The limitation of the present study was in the recording of original two-dimensional echocardiograms in parallel planes.

Computerized densitometry and color coding of [14C] deoxyglucose autoradiographs.

A computerized image processing system has been developed for quantitative analyses of autoradiographs obtained with the [14C]deoxyglucose method. The system is composed of standard, commercially available components and includes a scanning microdensitometer, computer, image memory and display system, and monochrome and color monitors. The associated computer programs are written in PASCAL. Autoradiographs are automatically scanned, and the optical density of each spot is digitized at a maximum resolution of 65,536 readings per 6.4 x 6.4 mm area and stored in memory. Images can be reconstructed from the data in memory, displayed on the monitors, and utilized for microdensitometric analyses or manipulated for image enhancement, enlargement, or weighted averaging of selected regions. The digitized data can also be utilized to solve the operational equation of the [14C]deoxyglucose method, and color-coded images of autoradiographs can be reconstructed so that each color represents a narrow range of the rate of glucose utilization. By means of this system, it is possible to generate quantitative metabolic maps that display the distribution of actual rates of local glucose utilization throughout the entire central nervous system in regions as small as 100 micrometers or less.

An attempt to analyze locomotion of leukemia cells by computer image processing

Phase contrast photographs of locomotive leukemia cells from a time lapse film were analyzed by an image processing computer system. Various structural and directional parameters were chosen to characterize dislocation and shape changes of a moving cell. A correlation could be established between the cellular image seen in time lapse films and the numerical shape configuration based on automated image analysis. It seems, therefore, that the parameters chosen represent a basis for further evaluation of the quantitative model of cellular locomotion.

Operating a nuclear medicine computer system with a remote mobile gamma camera

The introduction of mobile gamma cameras has allowed nuclear medicine studies to be performed on patients too ill to be brought to the Nuclear Medicine department. Ventilation-perfusion imaging and ECG-gated cardiac imaging require that provision be made for data processing. Tape drive systems allowing image and ECG data to be recorded and subsequently analysed are available. To overcome problems associated with magnetic tape data logging, a system has been implemented for the remote control of the department's image processing computer system which allows the collection of data from, and the transmission of the computer images to, the remote site via an existing cable network normally used for the transmission of closed circuit TV and audio signals. A gated image can be seen as soon as data collection is finished. If necessary a repeat view can then be taken immediately, before the tracer dissociates.

Computer analysis of left ventricular dynamic geometry in man

Analysis of left ventricular performance in 20 normal patients was undertaken using biplane cineangiography and a semiautomatic computer image processing system. The analysis included evaluation of volumes, ejection fraction, regional shortening, patterns of ejection and filling and, when simultaneous left ventricular pressure was recorded, stroke work, stroke power, wall stress and internal myocardial work. All of these data were calculated from digitized images stored permanently on digital magnetic tape, and can be reproduced without reanalysis of the cine film. Normal left ventricular function is described by an end-diastolic volume index of 82 ± 3 ml, an ejection fraction of 60 ± 2 percent, left ventricular mass index of 97 ± 6 g/m 2, peak first derivative of volume ( dV dt ) of 485 ± 28 ml/sec, anterior shortening of 48 ± 2.3 percent, inferior shortening of 33 ± 1.7 percent, lateral shortening of 29 ± 1.5 percent, anterior mean shortening velocity (Vcf, in percent of end-diastolic length [L]/sec) of 1.5 ± 0.1 L/sec, inferior Vcf of 1.1 ± 0.06 L/sec and lateral Vcf of 0.94 ± 0.2 L/sec, stroke work of 1.33 ± 0.21 joules, mean stroke power of 3.7 ± 0.62 joules/sec, integrated left ventricular pressure (tension-time index) of 2,866 ± 340 mm Hg-sec, and integrated stress (stress-time index) of 7,260 ± 765 (× 10 3) dynes sec/cm 2. Internal myocardial work was calculated from the strain energy. More Internal work was expended in circumferential than longitudinal shortening (circumferential, 0.69 ± 0.1 joules; longitudinal, 0.41 ± 0.08, P < 0.01), because hoop stress was greater than meridian stress (hoop, 201 ± 20 dynes/cm 3 × 10 3; meridian, 126 ± 13, P < 0.001). This analysis of left ventricular performance provides a reliable means for identifying abnormal ventricular function and may be more sensitive than any one measurement alone. The use of digital image processing makes this complex functional analysis of left ventricular performance feasible.

Errors in objects positioning with Centre of Gravity method

It is shown that location of objects (in the field of vision of “robot's eye”) with simple centre of gravity method (proposed by some authors) leads to severe errors in positioning. In the paper detailed quantitative analysis of two main types of these errors is carried out, as well as some methods of decreasing them are proposed, as applied in application programs for the computer image processing system CPO‐2.