A method for the digital image analysis of ceramic grains based on shape factor segmentation

A very simple and robust method for ceramics grains quantitative image analysis is presented. Based on the use of optimal imaging conditions for reflective light microscopy of bulk samples, a digital image processing routine was developed for shading correction, noise suppressing and contours enhancement. Image analysis was done for grains selected according to their concavities, evaluated by perimeter ratio shape factor, to avoid consider the effects of breakouts and ghost boundaries due to ceramographic preparation limitations. As an example, the method was applied for two ceramics, to compare grain size and morphology distributions. In this case, most of artefacts introduced by ceramographic preparation could be discarded due to the use of perimeter ratio exclusion range.

Road segment delineation using active testing principle and an edge-based post-processing strategy

This paper presents a semi-automated method for extracting road segments from medium-resolution images based on active testing and edge analysis. The method is based on two sequential and independent stages. Firstly, an active testing method is used to extract an approximated road centreline which is based on a sequential and local exploitation of the image. Secondly, an iterative strategy based on edge analysis and the approximated centreline is used to measure precisely the road centreline. Based on the results obtained using medium-resolution test images, the method seems to be very promising. In general, the method proved to be very accurate whenever the roads are characterized by two well-defined anti-parallel edges and robust even in the presence of larger obstacles such as trees and shadows.

Morphometric study by image analysis of Ag-stained nucleoli in thyroids bearing proliferating lesions

The Ag-NOR staining technique and image analysis were used to evaluate morphological parameters (area, perimeter and axis ratio) in nucleoli from normal thyroids and from thyroids bearing proliferating lesions (carcinomas, adenomas and hyperplasias). Regions with normal appearance located close to adenomatous and carcinomatous regions, in the thyroid of every patient, were also analyzed for comparison with the respective pathological regions and with normal thyroids. Statistical analysis of data for the nucleolar area and perimeter allowed the separation of adenomas and carcinomas from hyperplasias and normal tissue but not the two components in each of these two groups. However, if we look at the numbers, a sequence of increasing nucleolar mean areas in the order: normal, hyperplasia, adenoma and carcinoma may be observed, indicating the sequence of increasing rRNA requirements in these different kinds of cells. The axis ratio that denotes the nucleolar shape (round or oblong) did not show significant differences among tissues, suggesting that shape is not important in the characterization of these pathologies. Differences in nucleolar areas and perimeter between normal and affected regions from each patient were statistically significant for adenomas and carcinomas. When these normal regions were compared with the normal thyroids, significant differences were not obtained in the three evaluated parameters. The observations and their importance for histopathological diagnosis are discussed.

Dynamic programming approach for road centerline extraction from digital images

This paper presents a dynamic programming approach for semi-automated road extraction from medium-and high-resolution images. This method is a modified version of a pre-existing dynamic programming method for road extraction from low-resolution images. The basic assumption of this pre-existing method is that roads manifest as lines in low-resolution images (pixel footprint> 2 m) and as such can be modeled and extracted as linear features. On the other hand, roads manifest as ribbon features in medium- and high-resolution images (pixel footprint ≤ 2 m) and, as a result, the focus of road extraction becomes the road centerlines. The original method can not accurately extract road centerlines from medium- and high- resolution images. In view of this, we propose a modification of the merit function of the original approach, which is carried out by a constraint function embedding road edge properties. Experimental results demonstrated the modified algorithm's potential in extracting road centerlines from medium- and high-resolution images.

A photogrammetric method for single image orientation and measurement

The aim of this paper is to present a photogrammetric method for determining the dimensions of flat surfaces, such as billboards, based on a single digital image. A mathematical model was adapted to generate linear equations for vertical and horizontal lines in the object space. These lines are identified and measured in the image and the rotation matrix is computed using an indirect method. The distance between the camera and the surface is measured using a lasermeter, providing the coordinates of the camera perspective center. Eccentricity of the lasermeter center related to the camera perspective center is modeled by three translations, which are computed using a calibration procedure. Some experiments were performed to test the proposed method and the achieved results are within a relative error of about 1 percent in areas and distances in the object space. This accuracy fulfills the requirements of the intended applications. © 2005 American Society for Photogrammetry and Remote Sensing.

COX24 codes for a mitochondrial protein required for processing of the COX1 transcript

In most strains of Saccharomyces cerevisiae the mitochondrial gene COX1, for subunit 1 of cytochrome oxidase, contains multiple exons and introns. Processing of COX1 primary transcript requires accessory proteins factors, some of which are encoded by nuclear genes and others by reading frames residing in some of the introns of the COX1 and COB genes. Here we show that the low molecular weight protein product of open reading frame YLR204W, for which we propose the name COX24, is also involved in processing of COX1 RNA intermediates. The growth defect of cox24 mutants is partially rescued in strains harboring mitochondrial DNA lacking introns. Northern blot analyses of mitochondrial transcripts indicate cox24 null mutants to be blocked in processing of introns aI2 and aI3. The dependence of intron aI3 excision on Cox24p is also supported by the growth properties of the cox24 mutant harboring mitochondrial DNA with different intron compositions. The intermediate phenotype of the cox24 mutant in the background of intronless mitochondrial DNA, however, suggests that in addition to its role in splicing of the COX1 pre-mRNA, Cox24p still has another function. Based on the analysis of a cox14-cox24 double mutant, we propose that the other function of Cox24p is related to translation of the COX1 mRNA. © 2006 by The American Society for Biochemistry and Molecular Biology, Inc.

The application of distributed virtual machines for enterprise computer management: A two-tier network file system for image provisioning and management

In order to simplify computer management, several system administrators are adopting advanced techniques to manage software configuration of enterprise computer networks, but the tight coupling between hardware and software makes every PC an individual managed entity, lowering the scalability and increasing the costs to manage hundreds or thousands of PCs. Virtualization is an established technology, however its use is been more focused on server consolidation and virtual desktop infrastructure, not for managing distributed computers over a network. This paper discusses the feasibility of the Distributed Virtual Machine Environment, a new approach for enterprise computer management that combines virtualization and distributed system architecture as the basis of the management architecture. © 2008 IEEE.

JSEG-based image segmentation in computer vision for agricultural mobile robot navigation

This project aims to apply image processing techniques in computer vision featuring an omnidirectional vision system to agricultural mobile robots (AMR) used for trajectory navigation problems, as well as localization matters. To carry through this task, computational methods based on the JSEG algorithm were used to provide the classification and the characterization of such problems, together with Artificial Neural Networks (ANN) for pattern recognition. Therefore, it was possible to run simulations and carry out analyses of the performance of JSEG image segmentation technique through Matlab/Octave platforms, along with the application of customized Back-propagation algorithm and statistical methods in a Simulink environment. Having the aforementioned procedures been done, it was practicable to classify and also characterize the HSV space color segments, not to mention allow the recognition of patterns in which reasonably accurate results were obtained.

A regularized nonlinear diffusion approach for texture image denoising

In this paper a new partial differential equation based method is presented with a view to denoising images having textures. The proposed model combines a nonlinear anisotropic diffusion filter with recent harmonic analysis techniques. A wave atom shrinkage allied to detection by gradient technique is used to guide the diffusion process so as to smooth and maintain essential image characteristics. Two forcing terms are used to maintain and improve edges, boundaries and oscillatory features of an image having irregular details and texture. Experimental results show the performance of our model for texture preserving denoising when compared to recent methods in literature. © 2009 IEEE.

Cephalometric evaluation of surgical mandibular advancement

The treatment of Class II adult individuals with mandibular deficiency has been the combination of orthodontic treatment and orthognathic surgery. Therefore, a study was conducted in which cephalometric analysis was used to evaluate the influence of dentoalveolar decompensation in Class II patients submitted to orthodontic and surgical treatment for mandibular advancement, by bilateral osteotomy of the mandibular ramus. A sample of 15 leukoderma adult female patients were selected and three cephalometric radiographs of each patient, taken before the orthodontic treatment, before surgery and after at least 6 months postoperatively, were analyzed in a total of 45 roentgenograms. The tracings were made by the manual method and the points were digitalized using software. The results showed that values of SNB increased from 75.6 to 78.6°. The measures BNP and PGNP were reduced from -12.7 to -7.7 mm and -12.7 to -6.6 mm, respectively. For ANB there was a reduction of 3.23° (from 8.1° to 4.9°). Likewise, the values of AOBO were diminished by 6.3 mm (from 7.6 to 1.3 mm), and in the values of OJ there was a reduction of 5.7 mm (from 9 to 3.3 mm). It was concluded that the pre-surgical orthodontic treatment promoted minimal and variable dental and skeletal changes in the final result. The surgical treatment caused significant skeletal changes, especially in the measurements related to the mandible (SNB, BNP, PGNP and SNPM) or indirectly to it (ANB, AOBO and OJ).

ANN statistical image recognition method for computer vision in agricultural mobile robot navigation

The main application area in this project, is to deploy image processing and segmentation techniques in computer vision through an omnidirectional vision system to agricultural mobile robots (AMR) used for trajectory navigation problems, as well as localization matters. Thereby, computational methods based on the JSEG algorithm were used to provide the classification and the characterization of such problems, together with Artificial Neural Networks (ANN) for image recognition. Hence, it was possible to run simulations and carry out analyses of the performance of JSEG image segmentation technique through Matlab/Octave computational platforms, along with the application of customized Back-propagation Multilayer Perceptron (MLP) algorithm and statistical methods as structured heuristics methods in a Simulink environment. Having the aforementioned procedures been done, it was practicable to classify and also characterize the HSV space color segments, not to mention allow the recognition of segmented images in which reasonably accurate results were obtained. © 2010 IEEE.

Trypanosoma cruzi: Evaluation of (-)-cubebin derivatives activity in the messenger RNAs processing

No fully effective treatment has been developed since the discovery of Chagas' disease. Since drug-resistant Trypanosoma cruzi strains are occurring and the current therapy is effective in the acute phase but with various adverse side effects, more studies are needed to characterize the susceptibility of T. cruzi to new drugs. Pre-mRNA maturation in trypanosomatids occurs through a process called trans-splicing, which is unusual RNA processing reaction, and it implies the processing of polycistronic transcription units into individual mRNAs; a short transcript spliced leader (SL RNA) is trans-spliced to the acceptor pre-mRNA, giving origin to the mature mRNA. Cubebin derivatives seem to provide treatments with less collateral effects than benznidazole and showed similar or better trypanocidal activities than benznidazole. Therefore, the cubebin derivatives ((-)-6,6′-dinitrohinokinin (DNH) and (-)-hinokinin (HQ)) interference in the mRNA processing was evaluated using T. cruzi permeable cells (Y and BOL (Bolivia) strains) following by RNase protection reaction. These substances seem to intervene in any step of the RNA transcription, promoting alterations in the RNA synthesis, even though the RNA processing mechanism still occurs. Furthermore, HQ presented better activity against the parasites than DNH, meaning that BOL strain seems to be more resistant than Y. © 2011 Springer-Verlag.

Improving synthetic aperture image by image compounding in beamforming process

In this work, signal processing techniques are used to improve the quality of image based on multi-element synthetic aperture techniques. Using several apodization functions to obtain different side lobes distribution, a polarity function and a threshold criterium are used to develop an image compounding technique. The spatial diversity is increased using an additional array, which generates complementary information about the defects, improving the results of the proposed algorithm and producing high resolution and contrast images. The inspection of isotropic plate-like structures using linear arrays and Lamb waves is presented. Experimental results are shown for a 1-mm-thick isotropic aluminum plate with artificial defects using linear arrays formed by 30 piezoelectric elements, with the low dispersion symmetric mode S0 at the frequency of 330 kHz. © 2011 American Institute of Physics.

Image categorization through optimum path forest and visual words

Different from the first attempts to solve the image categorization problem (often based on global features), recently, several researchers have been tackling this research branch through a new vantage point - using features around locally invariant interest points and visual dictionaries. Although several advances have been done in the visual dictionaries literature in the past few years, a problem we still need to cope with is calculation of the number of representative words in the dictionary. Therefore, in this paper we introduce a new solution for automatically finding the number of visual words in an N-Way image categorization problem by means of supervised pattern classification based on optimum-path forest. © 2011 IEEE.

Assessment of eyebrow position before and after upper eyelid blepharoplasty

Objective: Assess the occurrence of secondary brow ptosis after upper lid blepharoplasty. Methods: Forty-five individuals (n90 brows) submitted to upper lid blepharoplasty, were assessed by means of a comparative analysis using pre- and post-operatively digital photographs, in the primary position of the eye. The images were processed using ImageJ software, transferred to a computer, to an electronic Microsoft Excel 2002® worksheet. Angular measurements were used, taking the lateral canthal angle of the brow, the most medial point of the brow, the medial canthal angle and the lateral canthal angle of the lid as anatomical reference points. When the outer angles were reduced or the inner angles increased after surgery this was considered a brow ptosis. Individuals who had undergone lid surgery associated with the eyebrow, previous eyebrow surgery and those with eyelid ptosis were excluded. The difference between the pre-operative and post-operative measurements were analyzed statistically using the Student's t-test for paired samples and the angular variation was compared with their corresponding contralateral sample using Wilcoxon's non-parametric test. Results: The measurements obtained after the blepharoplasty show significant variations from those before the surgery, indicating that the correction of redundant tissues in the brow accentuates the tendency of the eyebrow to move down. The alterations are more important in the lateral portion of the eyebrow and they occur bilaterally. Conclusion: The assessment of angular measurements obtained pre- and post-operatively showed that there are secondary changes in the position of the eyebrow as a result of upper eyelid blepharoplasty. © 2012 Informa Healthcare USA, Inc.