Use Of Digital Image Analysis Research Articles

Using digital image analysis and spectral reflectance data to quantify damage by greenbug (Hemitera: Aphididae) in winter wheat

The usefulness of digital image analysis and spectral reflectance data to quantify damage by greenbugs ( Schizaphis graminum (Rondani)) was evaluated for two winter wheat ( Triticum aestivum L.) fields, three field experiments, and one greenhouse experiment in Oklahoma and Texas. A hyperspectral field spectrometer and a digital camera were used to record reflectance and to acquire images over 0.25-, 0.37-, and 1-m 2 greenbug-damaged wheat canopies. A large number of spectral vegetation indices compiled from the literature were calculated and relationship to damage by greenbugs was investigated. The mean percent damage by greenbugs estimated through digital image analysis varied from 13 ± 1/0.25 to 73 ± 7/0.37 m 2. The mean greenbug abundance ranged from 191 ± 22/0.25 to 54,209 ± 7908/0.37 m 2. Correlation analyses showed strong associations between damage by greenbugs in wheat and spectral vegetation indices. Correlation coefficient ranged from 0.82 to −0.98. These results suggest that remote sensing using spectral reflectance and digital images can be nondestructive, rapid, cost-effective, and reproducible techniques to determine damage by greenbugs in wheat with repeatable accuracy and precision. Together with the existing spectral indices, two versions of a new index algorithm are suggested in this paper.

Advances in the diagnosis of cholangiocarcinoma in patients with primary sclerosing cholangitis

Advances in the diagnosis of cholangiocarcinoma in patients with primary sclerosing cholangitis

Assessment of the 3D Localization of Metallic Nanoparticles in Pd/SiO2 Cogelled Catalysts by Electron Tomography

The purpose of this study is to analyze the localization of palladium nanoparticles within their silica support, in two heterogeneous catalysts synthesized by the sol-gel process, with different metal loadings. Electron tomography demonstrates that the palladium particles are localized deep inside the silica skeleton. The use of digital image analysis further shows that the dispersion of palladium is optimal in the sample with the lowest loading. The particles are regularly spaced in the middle of the silica skeleton, with a distance between them comparable to the diameter of the struts of silica.

Digital image analysis for the evaluation of the inflammatory infiltrate in psoriasis

Traditionally the evaluation of the cellular infiltrate and protein expression in skin tissue sections is done by manual quantification. However, for reliable evaluation of histology in the development of new anti-psoriatic treatments there is a need for a more time-efficient and reproducible method. To test the use of digital image analysis (DIA) in this situation we compared the assessment of immunohistochemically stained skin sections with the more traditional manual quantification (MQ) and semi-quantitative analysis (SQA). The number of CD3+ T cells and the expression of E-selectin were evaluated in stained paired skin biopsies from 11 patients with chronic plaque psoriasis before and after initiation of anti-psoriasis therapy. We observed significant correlations between MQ and DIA for the number of T cells (epidermis: r=0.88, P< or =0.01, dermis r=0.87, P< or =0.01). Both DIA and MQ were equally effective in detecting reductions of T-cell numbers in active-treated patients. MQ took 20 h, compared to 6 h for DIA. We also observed significant correlations between SQA and DIA for the expression of E-selectin (r=0.88, P< or =0.01), although DIA was more sensitive than SQA to detect (early) changes. SQA took 10 h, compared to 4 h for DIA. In conclusion, the quantification of the inflammatory infiltrate in psoriatic lesional skin by DIA generated similar results as MQ and SQA in a reliable, reproducible and higher time efficient fashion.

In vitro quantification of changes in human dentine tubule parameters using SEM and digital analysis

Dentine hypersensitivity is recognized as a pain arising from fluid movement within dentine tubules that are open to the oral environment. Blocking the tubules is considered to be the principal aim of treatment, and the accurate assessment of tubule occlusion is the primary goal of many in vitro studies. This assessment usually comprises either measuring tubule permeability or scanning electron microscope examination of the dentine surface. Several scanning microscopy studies have claimed to quantify tubule occlusion, but are descriptive, qualitative or semi-quantitative evaluations. The present study was undertaken to assess the use of digital image analysis in quantifying the effectiveness of a selected desensitizing agent from micrographs of control and treated dentine surfaces. Using a dentine disc model, an accurate methodology was sought to investigate the occluding potential of Butler Protect (J.O. Butler, Chicago, IL, USA). Subjective examination of the images indicated there was little difference after a single application, but considerable effect after 20 applications. Quantitative digital analysis of a test image, demonstrated reproducibility between two examiners when used in fully- and semi-automated mode. After a single application of Butler Protect, multilevel statistical modelling demonstrated decreases in tubule area and maximum, minimum and mean diameter measurements (P < 0.001), whereas single level analysis showed increases in area and maximum and mean diameters. Multiple application of Butler Protect demonstrated even greater decreases in all parameters (P < 0.001). This quantitative methodology was reproducible between examiners and, when combined with good controls and multilevel statistical modelling, was able to discriminate a single application of desensitizing agent.

Real Time Imaging and Quantitative Evaluation of the Emphysematous Lung by Infrared Thoracoscopy in Experimental Dogs

To accurately excise emphysematous lung tissue in volume reduction surgery, we projected a digitally analyzed excision line on the real time image obtained by infrared thoracoscopy (IRT) with indocyanine green (ICG) intravenous injection. Emphysema was created in the canine lung by intrabronchial injection of elastase. We examined the emphysematous lung by IRT after intravenous injection of ICG. A digitized static image was obtained and analyzed in real time during the surgery. The color densities on the image were measured and the color density ratios (CDRs) calculated. We resected lung areas where the CDR was 1.0 or less. Resected and residual lung areas were examined microscopically. Microscopically, areas displayed as white by IRT with intravenous injection of ICG were emphysematous, and areas displayed as blue were normal. Areas with a CDR of 1.0 or less were emphysematous, and we were able to determine an appropriate excision line by connecting sample points with a CDR of 1.0. Use of digital image analysis combined with IRT after ICG injection enabled us to remove emphysematous regions accurately.

An increasing incidence of cholangiocarcinoma: Why?

An increasing incidence of cholangiocarcinoma: Why?

Use of digital image analysis, viability stains, and germination assays to estimate conventional and glyphosate‐resistant cotton pollen viability

AbstractBecause the success of labor‐intensive hand crosses by breeders is dependent upon pollen viability, quick, simple, and inexpensive methods for viability assessment are of interest. Four such cotton pollen viability assays were compared to determine differences in viability estimates, and relative accuracy by correlation to seed set. The methods compared were Brewbaker &amp; Kwack (B &amp; K) medium, B &amp; K medium plus aniline blue, a fluorochromatic reaction method (FCR), and Alexander's stain. Additionally, digital images of germinated pollen grains were analyzed by means of morphometry software to quantify pollen tube area per pollen grain, as a proposed additional method of assessing viability. Pollen from conventional, nontreated glyphosate‐resistant (GR) and glyphosate‐treated GR cotton (Gossypium hirsutum L.) plants was tested by each method. Glyphosate treatments to GR cotton reduced pollen viability and corresponding seed set in all methods tested. Pollen germination measured by the B &amp; K method was most closely related to seed set per boll, while Alexander's stain gave the highest estimates of viability. The FCR method indicated that many pollen grains from glyphosate‐treated GR cotton were irregularly shaped and only partially flourescein diacetate (FD) stained. All methods tested showed similar high correlation (0.7–0.8) of pollen viability to seed set. Morphometric analysis of digital images of germinated pollen found the greatest pollen tube area to pollen grain ratio with B &amp; K medium + 30 mM sucrose. Because the B &amp; K method most closely predicted the linear magnitude of seed set reduction to reduced pollen viability, allowed the use of morphometry software analysis, and was one of the simplest and least equipment‐demanding methods, it may provide broad utility for those assessing cotton pollen viability.

Digital Image Analysis of Sweetpotato Storage Roots in Herbicide Trials

Digital image analysis (DIA) was evaluated for use in assessing size and shape attributes of sweetpotato [Ipomoea batatas (L.) Lam.] storage roots in herbicide studies. Digital image files of U.S. no. 1 storage roots were taken using a digital camera. Image analysis was performed using a publicly available software package. Eight size and shape attributes were measured and subjected to univariate and multivariate procedures. DIA revealed differences for storage root width and roundness attributes. Principal component analysis suggested that storage root length, width, and roundness best described the variability of the storage root sample. The results demonstrate the potential use of DIA in augmenting data from sweetpotato herbicide trials as well as other investigations that require information about storage root size and shape responses.

Effects of Pretreatments on Print Qualities of Digital Textile Printing

Research presented in this paper addresses some preliminary attempts to establish the relationship between the pretreatment and the digital printing quality by the use of digital image analysis and optical microscopy. As in traditional textile printing, miss color, out of fit patterns, mottle, and color defects due to poor ink surface coverage can occur in digital printing. More specifically, defects in the digital printing of textile fabrics can be categorized into color-related issues (color gamut, color matching, light fastness, wash fastness and uniformity) and appearance-related issues (line definition, dot geometry, penetration, intensity and color registration). Woven and knitted cotton fabrics were treated with twelve formulations including ingredients like alginate, silicone and silica. Printed patterns were analyzed using an optical microscope and a digital image analysis to quantify the print qualities in terms of color-related metrics (L*a*b*) and appearance-related metrics (line width). Results show that digital textile printing quality on cotton fabrics can be optimized with appropriate pretreatments.

Use of fourier transforms to define landscape scales of analysis for disturbances: a case study of thinned and unthinned forest stands

Various disturbances such as disease and management practices causecanopy gaps that change patterns of forest stand structure. This study examinedthe usefulness of digital image analysis using aerial photos, FourierTranforms,and cluster analysis to investigate how different spatial statistics areaffected by spatial scale. The specific aims were to: 1) evaluate how a Fourierfilter could be used to classify canopy gap sizes objectively, 2) determinewhich statistics might be useful for detecting and measuring disturbanceimpacts, and 3) examine the potential for this method to determine spatialdomains in a pair of ponderosa pine (Pinusponderosa) stands in the Black Hills of South Dakota,USA.The eventual goal is to develop an operational method of assessing the impactsof natural disturbances such as disease. Results indicated that several spatialmetrics discriminated between harvested and unharvested stands. We hypothesizethat these metrics will be useful as spatial measures of disease impact if theanalyses are performed on specific size classes of forest gaps.

The effect of mothers on bubble size distributions in flotation pulp phases and surface froths

Froth dynamics, i.e. the stability and mobility of the froth, are crucial indicators of various important features of flotation systems. For example, it is desirable that the froth collapses as soon as possible after it is skimmed off the cell in order to curtail losses in throughput. On the other hand, if the froth is too prone to collapse, it will not be sufficiently stable to support its load prior to skimming. Likewise, the mobility of the froth gives similar information on the performance of the flotation cell. For example, a sharp contrast can be observed between dry viscous (immobile) froths and watery runny froths with high mobility. Several authors have recently shown that analysis of the structure of the froth in a flotation cell can be used to assess the performance of the cell. This implies that there is a close relationship between the bubble size distribution in the pulp and froth phases. Until very recently, it was not possible to verify this hypothesis direct, since reliable measurements of bubble size distributions in especially the froth phase could not be obtained. With recent improvements in the machine vision technology originally developed at the University of Stellenbosch, it is now possible to measure bubble size distributions and stability in froth structure with a high degree of accuracy. Unlike previous methods, these improved algorithms can provide a detailed map of flow patterns in the froths, which can give a significantly better idea of operating conditions in the flotation cell. Consequently, in this experimental study the bubble size distribution in the pulp phase of a laboratory flotation cell was measurement with a capillary tube system (UCT bubble size analyser), while the bubble size distribution in the froth phase was measured by use of digital image analysis. The relationship between these bubble size distributions in the pulp and froth phases is discussed.

The use of digital image analysis in the study of laminated sediments

The use of digital image analysis for the investigation of many natural phenomena is not novel. A vast amount of literature exists on its application to the study of a diversity of physical characteristics from many environments. The power of this tool is now being realised, however, in the study of sediments, from both marine and lacustrine environments. The advent of image processing applications for use in a personal computing environment, and the availability of high resolution digital video cameras, are serving to bring the technique to the desktops of many researchers. This paper will attempt to review those techniques which may be found useful by researchers contemplating the use of image analysis in this type of study, and in particular those who need to count laminations in order to construct a chronology, or to compile time series from lamina thickness or composition, for comparison with those derived from other datasets. Much of the information may be found already in print, but it derives from many disciplines, and does not seem to have been documented previously in this connection.

Novel technique for measuring the size distribution of granules from anaerobic reactors for wastewater treatment

A new technique for measuring the size distribution of anaerobic granular sludge, which involves the use of digital image analysis, is presented. Sludge samples are embedded in gelatin, spread over glass dishes, which are then placed over a flat-bed scanner where an image is captured. The images are processed with an image analysis software. The technique is simple, reliable and does not need any special equipment. © Rapid Science Ltd. 1998

Reproducibility of Digital Image Analysis for Measuring Corneal Haze After Myopic Photorefractive Keratectomy

To evaluate the usefulness of digital image analysis for quantifying corneal haze by determining the reproducibility of its measurements at the corneal plane. In a prospective study, 20 randomly selected eyes that had undergone myopic photorefractive keratectomy were photographed focusing the slit beam on their anterior corneal surface. Each photograph was examined using computer image analysis techniques that detect the edge of the reticular pattern of the image. Quantification of the difference between two areas, treated and adjacent untreated cornea, each containing 3,750 pixels with a resolution of 256 gray levels, was performed. Intra-analyzer variation was determined by evaluating the photographs obtained by two analyzers under standard conditions on four separate visits. Interanalyzer variation was calculated using one measurement and the mean of the four measurements. The pooled standard deviation of the measurements for the analyzers was 0.63 and 0.62 gray levels (coefficient of variation, 4.1% and 3.3%). An association between less severe haze measurements and higher reproducibility scores was found (r = .42; P = .007). The mean interanalyzer variation was smaller for the average of four measurements, 0.55 +/- 0.37 gray levels, than for one measurement, 0.94 +/- 0.73 gray levels (P = .014). Good reproducibility for haze measurements by digital image analysis of the differences between the treated and adjacent untreated corneal areas was obtained. When the average of four measurements was used instead of a single measurement, interanalyzer reproducibility increased significantly. This new technique may be used to quantify and analyze corneal haze after myopic photorefractive keratectomy.

The use of digital image analysis of chromatin texture in Feulgen-stained nuclei to predict recurrence of low grade superficial transitional cell carcinoma of the bladder.

Identifying a marker enabling prediction of recurrence in the group of superficial transitional cell carcinomas (sTCCs) of the bladder remains an important challenge today. This report quantitatively describes chromatin patterns with respect to such sTCC recurrence. Twenty-nine patients with sTCCs who did not exhibit tumor recurrence within a minimum of 24 months were compared with 21 patients with sTCCs who exhibited tumor recurrence two or three times in a 24-month period, for a total of 74 sTCCs. Quantitative chromatin pattern description was performed by the digital cell image analyses of Feulgen-stained nuclei. Six morphonuclear parameters were thus described and subsequently used to determine a score, allowing biological behavior of sTCCs to be described, i.e., recurrence versus non-recurrence in one calculation step. DNA ploidy level was also determined in each sTCC by assessing its DNA histogram type. Of 32 patients with Grade 1 pathologically classified pTa/pT1 tumors, DNA ploidy level determination permitted correct prediction of tumor nonrecurrence or recurrence of 13 (41%), whereas determination of the score values enabled prediction of nonrecurrence or recurrence of 25 (78%). Combining DNA ploidy level data and the score values enabled recurrence or nonrecurrence to be predicted for 29/32 of the patients (91%). The quantitative description of chromatin patterns by digital cell image analysis of Feulgen-stained nuclei can provide helpful information, in addition to DNA ploidy level determination, in predicting tumor recurrence of low grade superficial transitional cell carcinomas of the bladder.

Use of digital image analysis to estimate fluid permeability of porous materials: Application of two-point correlation functions

Scanning electron microscope images of cross sections of several porous specimens have been digitized and analyzed using image processing techniques. The porosity and specific surface area may be estimated directly from measured two-point spatial correlation functions. The measured values of porosity and image specific surface were combined with known values of electrical formation factors to estimate fluid permeability using one version of the Kozeny-Carman empirical relation. For glass bead samples with measured permeability values in the range of a few darcies, our estimates agree well (±10–20%) with the measurements. For samples of Ironton-Galesville sandstone with a permeability in the range of hundreds of millidarcies, our best results agree with the laboratory measurements again within about 20%. For Berea sandstone with still lower permeability (tens of millidarcies), our predictions from the images agree within 10–30%. Best results for the sandstones were obtained by using the porosities obtained at magnifications of about 100× (since less resolution and better statistics are required) and the image specific surface obtained at magnifications of about 500× (since greater resolution is required).

Computer analysis of a high-speed film of the plane turbulent mixing layer

To evaluate the usefulness of digital image analysis in extracting quantitative information from flow pictures we have studied a 16 mm ciné film of a turbulent mixing layer. A sequence of 373 frames is digitized and analysed to isolate and measure the concentration eddies that constitute the large structure and to follow their individual evolution in time. As a result, statistics are given on the life history of the eddies, the structure of the amalgamation process and the amount of entrainment, as measured by area change, due to amalgamation as compared to the total. It is found that most of the entrainment occurs during the normal life of eddies and not during pairing. Mixing intermittency is computed from the observed shape of the eddies and seen to compare well with previous measurements. The significance of these results in modelling the mixing layer is discussed briefly and some comments are given on the general usefulness of the techniques presented.