314 research outputs found
Unsupervised detection and localization of structural textures using projection profiles
Cataloged from PDF version of article.The main goal of existing approaches for structural texture analysis has been the identification of repeating texture primitives and their placement patterns in images containing a single type of texture. We describe a novel unsupervised method for simultaneous detection and localization of multiple structural texture areas along with estimates of their orientations and scales in real images. First, multi-scale isotropic filters are used to enhance the potential texton locations. Then, regularity of the textons is quantified in terms of the periodicity of projection profiles of filter responses within sliding windows at multiple orientations. Next, a regularity index is computed for each pixel as the maximum regularity score together with its orientation and scale. Finally, thresholding of this regularity index produces accurate localization of structural textures in images containing different kinds of textures as well as non-textured areas. Experiments using three different data sets show the effectiveness of the proposed method in complex scenes.(C)2010 Elsevier Ltd. All rights reserved
A Preliminary Technique for the Isolation and Culture of Brown Trout (Salmo trutta macrostigma, Dumeril, 1858) Spermatogonial Stem Cell
This study was aimed to find a practical technique for isolation and culture spermatogonial stem cells from male brown trout (Salmo trutta macrostigma). Twelve wild juvenile male were obtained from Kılıç Trout Fish Farm (Kahramanmaraş, Turkey). The juveniles were taken alive to the aquaria unit and stored in a 1000-liter capacity fiberglass tank. In order to identify the best size, age and testis structure of S.t. macrostigma for spermatogonial stem cell isolation and culture. Morphological and histological testis conditions were assessed. Fish were anesthetized with 0.04% 2-phenoxethanol. The surface of the fish was sterilized with 70% ethanol. Twelve fish were divided into two groups for enzyme digestion, and each group was divided into two replicates (three fish per replicate). Testis tissue of group one were digested by 0.25% trypsin- EDTA, and testis tissues of group two were digested by 0.05% trypsin-EDTA. At the end of the trial, first, the best age, size and weight of the male fish for spermatogonial stem cell isolation and culture were identified as 5+ month old, 12.13±1.5 cm, 19, 25±7.05 g respectively. Then, the highest spermatogonial stem cells were measured in the stage one and two of the testes. Finally, isolation and culture conditions were optimized for male S.t. macrostigma. Spermatogonial stem cell isolation and culture techniques were defined for fish in order to be used in surrogate reproduction technologies and gene transfer systems
COVID-19 Vaccine Acceptance is associated with Vaccine Hesitancy, Perceived Risk and Previous Vaccination Experiences
Late-Onset Glaucoma-Filtrating Bleb Leak in a Penetrating Keratoplasty Patient: A Case Report
Introduction. Late-onset bleb leaks occur more frequently after the use of adjunctive antimetabolites and require surgical management to seal and preserve filtrating bleb. Case Presentation. A 48-year-old female presented with decreased visual acuity for five days in her left eye. She had a left penetrating keratoplasty one year earlier and two trabeculectomies 7 years earlier. Visual acuity was hand motions, intraocular pressure was 3 mmHg, corneal graft was clear, mature cataract was present, and axial length was 30.48 mm. The conjunctiva covering the superotemporal sclerotomy was avascular, flat, and partially lost. After heavily painting the bleb with a fluorescein, late-onset point leak was revealed. Overlying conjunctiva was excised. The atrophic, irregular, and partially absent scleral flap was covered by a processed human pericardium graft and conjunctival advancement. Postoperatively, intraocular pressure stabilized around 16 mmHg. After four months, phacoemulsification and intraocular lens implantation were performed. Visual acuity did not exceed 0.1 (in decimal notation) due to degenerative myopia-related macular atrophy. Corneal graft remained clear at her 6-month followup period. Conclusion. Surgical bleb revision using a pericardium graft and conjunctival advancement seems to be an effective method for treating late bleb leaks. However, careful follow-up is required for detecting recurrent leaks and elevated intraocular pressure
Automatic detection and segmentation of orchards using very high-resolution imagery
Cataloged from PDF version of article.Spectral information alone is often not sufficient to distinguish certain terrain classes such as permanent crops like orchards, vineyards, and olive groves from other types of vegetation. However, instances of these classes possess distinctive spatial structures that can be observable in detail in very high spatial resolution images. This paper proposes a novel unsupervised algorithm for the detection and segmentation of orchards. The detection step uses a texture model that is based on the idea that textures are made up of primitives (trees) appearing in a near-regular repetitive arrangement (planting patterns). The algorithm starts with the enhancement of potential tree locations by using multi-granularity isotropic filters. Then, the regularity of the planting patterns is quantified using projection profiles of the filter responses at multiple orientations. The result is a regularity score at each pixel for each granularity and orientation. Finally, the segmentation step iteratively merges neighboring pixels and regions belonging to similar planting patterns according to the similarities of their regularity scores and obtains the boundaries of individual orchards along with estimates of their granularities and orientations. Extensive experiments using Ikonos and QuickBird imagery as well as images taken from Google Earth show that the proposed algorithm provides good localization of the target objects even when no sharp boundaries exist in the image data. © 2012 IEEE
Unsupervised detection and localization of structural textures using projection profiles
The main goal of existing approaches for structural texture analysis has been the identification of repeating texture primitives and their placement patterns in images containing a single type of texture. We describe a novel unsupervised method for simultaneous detection and localization of multiple structural texture areas along with estimates of their orientations and scales in real images. First, multi-scale isotropic filters are used to enhance the potential texton locations. Then, regularity of the textons is quantified in terms of the periodicity of projection profiles of filter responses within sliding windows at multiple orientations. Next, a regularity index is computed for each pixel as the maximum regularity score together with its orientation and scale. Finally, thresholding of this regularity index produces accurate localization of structural textures in images containing different kinds of textures as well as non-textured areas. Experiments using three different data sets show the effectiveness of the proposed method in complex scenes. © 2010 Elsevier Ltd. All rights reserved
A Fast Alignment Scheme for Automatic OCR Evaluation of Books
This paper aims to evaluate the accuracy of optical character recognition (OCR) systems on real scanned books. The ground truth e-texts are obtained from the Project Gutenberg website and aligned with their corresponding OCR output using a fast recursive text alignment scheme (RETAS). First, unique words in the vocabulary of the book are aligned with unique words in the OCR output. This process is recursively applied to each text segment in between matching unique words until the text segments become very small. In the final stage, an edit distance based alignment algorithm is used to align these short chunks of texts to generate the final alignment. The proposed approach effectively segments the alignment problem into small subproblems which in turn yields dramatic time savings even when there are large pieces of inserted or deleted text and the OCR accuracy is poor. This approach is used to evaluate the OCR accuracy of real scanned books in English, French, German and Spanish
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