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Scalable Kernel Correlation Filter with Sparse Feature Integration

Andres Solis Montero, Jochen Lang, Robert Laganiere
2015 2015 IEEE International Conference on Computer Vision Workshop (ICCVW)  
Correlation filters for long-term visual object tracking have recently seen great interest. Although they present competitive performance results, there is still a need for improving their tracking capabilities. In this paper, we present a fast scalable solution based on the Kernalized Correlation Filter (KCF) framework. We introduce an adjustable Gaussian window function and a keypoint-based model for scale estimation to deal with the fixed size limitation in the Kernelized Correlation Filter.
more » ... Furthermore, we integrate the fast HoG descriptors and Intel's Complex Conjugate Symmetric (CCS) packed format to boost the achievable frame rates. We test our solution using the Visual Tracker Benchmark and the VOT Challenge datasets. We evaluate our tracker in terms of precision and success rate, accuracy, robustness and speed. The empirical evaluations demonstrate clear improvements by the proposed tracker over the KCF algorithm while ranking among the top state-of-theart trackers.
doi:10.1109/iccvw.2015.80 dblp:conf/iccvw/MonteroLL15 fatcat:jduprxxmjzb2lgjzduxn64rlau

Colour and texture based pyramidal image segmentation

Milos Stojmenovic, Andres Solis-Montero, Amiya Nayak
2010 2010 International Conference on Audio, Language and Image Processing  
The goal of image segmentation is to partition an image into regions that are internally homogeneous and heterogeneous with respect to other neighbouring regions. We build on the pyramid image segmentation work proposed by [BHR] and [SSN] by introducing a mixture of colour and texture cues in order to more accurately group regions. Statistical comparison of each colour channel separately along with edge intensity and orientation histogram comparison were the cues used for region merging. The
more » ... ut image size is no longer constrained as in [BHR], [SSN] and other similar regular pyramid based approaches due to a modification of the pyramid construction rule. The new algorithm is tested on a set of images from the Berkeley image segmentation benchmark set. Our algorithm is fast (produces segmentations within seconds), results in the correct segmentation of elongated and large regions, very simple compared to plethora of existing algorithms, and appears competitive in segmentation quality with the best publicly available implementations.
doi:10.1109/icalip.2010.5685096 fatcat:7rpd337agrec3g4mdk5kahndcq

Framework for Natural Landmark-based Robot Localization

Andres Solis Montero, Hicham Sekkati, Jochen Lang, Robert Laganière, Jeremy James
2012 2012 Ninth Conference on Computer and Robot Vision  
In this paper we present a framework for visionbased robot localization using natural planar landmarks. Specifically, we demonstrate our framework with planar targets using Fern classifiers that have been shown to be robust against illumination changes, perspective distortion, motion blur, and occlusions. We add stratified sampling in the image plane to increase robustness of the localization scheme in cluttered environments and on-line checking for false detection of targets to decrease false
more » ... ositives. We use all matching points to improve pose estimation and an off-line target evaluation strategy to improve a priori map building. We report experiments demonstrating the accuracy and speed of localization. Our experiments entail synthetic and real data. Our framework and our improvements are however more general and the Fern classifier could be replaced by other techniques.
doi:10.1109/crv.2012.25 dblp:conf/crv/MonteroSLLJ12 fatcat:unkzvdvdlnbrhh5vvsqclzxv7q

ANTIFUNGAL ACTIVITY SCREENING OF ANTARCTIC ACTINOBACTERIA AGAINST PHYTOPATHOGENIC FUNGI

Andrés Santos, Kattia Núñez-Montero, Claudio Lamilla, Mónica Pavez, Damián Quezada-Solís, Leticia Barrientos
2020 Acta Biológica Colombiana  
(Núñez-Montero and Barrientos, 2018).  ...  Bacteria inhabiting Antarctica have adopted peculiar survival strategies to achieve competitive advantages (Núñez-Montero and Barrientos, 2018) .  ... 
doi:10.15446/abc.v25n2.76405 fatcat:gdytoum3vzajbaafwzvrbog5gm

Robust Detection of Corners and Corner-line Links in Images

Andres Solis Montero, Milos Stojmenovic, Amiya Nayak
2010 2010 10th IEEE International Conference on Computer and Information Technology  
We define corner points in an image as the intersections among detected straight line segments, and propose an algorithm that detects corners from such a definition. Our corner detection algorithm CLDC then makes use of the LDC (Line Detection using Contours) algorithm from [19], which outputs the list of all detected line segments together with their endpoints. Each line segment is extended in a post-processing step. CLDC (Corners from LDC) then finds corners in O((n+I) log n) time, where n
more » ... I are the number of endpoints the intersections of line segments, respectively. Detected corners are linked via line segments that define them. Such an output of the corner detection algorithm is a novel concept. The algorithm is comparable in time complexity with other algorithms, while providing more information about the line segments in the image. CLDC is robust to image transformations, such as rotation and translations. Our CLDC is compared to some existing algorithm, and its advantages are demonstrated.
doi:10.1109/cit.2010.109 dblp:conf/IEEEcit/MonteroSN10 fatcat:mden2svamnhgvdq4jvctra4x3q

Bacterial Communities in Fecal Samples of Myotis chiloensis from Southern, Chile

Kattia Núñez-Montero, Andrés Santos, Damián Quezada-Solís, Jaime Martínez-Urtaza, Fulgencio Lisón, Leticia Barrientos
2021 International Journal of Morphology  
Núñez-Montero and CONICYT-PFCHA/Doctorado Nacional/2017-21171392 to A. Santos; Fundación para la Innovación Agraria (FIA).  ...  NÚÑEZ-MONTERO, K.; SANTOS, A.; QUEZADA-SOLÍS, D.; MARTÍNEZ-URTAZA, J.; LISÓN, F. & BARRIENTOS, L. Bacterial communities in fecal samples of Myotis chiloensis from Southern, Chile. Int. J.  ...  NÚÑEZ-MONTERO, K.; SANTOS, A.; QUEZADA-SOLÍS, D.; MARTÍNEZ-URTAZA, J.; LISÓN, F. & BARRIENTOS, L. Bacterial communities in fecal samples of Myotis chiloensis from Southern, Chile. Int. J.  ... 
doi:10.4067/s0717-95022021000100057 fatcat:3c5niy2r7zbzjopl4d4ekckw7u

Co-parent selection for fast region merging in pyramidal image segmentation

Milos Stojmenovic, Andres Solis-Montero, Amiya Nayak
2010 2010 2nd International Conference on Image Processing Theory, Tools and Applications  
The goal of image segmentation is to partition an image into regions that are internally homogeneous and heterogeneous with respect to other neighbouring regions. We build on the pyramid image segmentation work proposed by 131 and 191 by making a more efficient method by which children chose parents within the pyramid structure. Instead of considering only four immediate parents as in 131, in 191 each child node considers the neighbours of its candidate parent, and the candidate parents of its
more » ... eighbouring nodes in the same level. In this paper, we also introduce the concept of a co-parent node for possible region merging at the end of each iteration. The new parents of the former children are co-parent candidates as if they are similar. The co-parent is chosen to be the one with the largest receptive field among candidate co parents. Each child then additionally considers one more candidate, the co-parent of the previous parent. Other steps in the algorithm, and its overall layout, were also improved. The new algorithm is tested on a set of images. Our algorithm is fast (produces segmentations within seconds), results in the correct segmentation of elongated and large regions, very simple compared to plethora of existing algorithms, and appears competitive in segmentation quality with the best publicly available implementations. The major improvement over 191 is that it produces visually appealing results at earlier levels of pyramid segmentation, and not only at the top one.
doi:10.1109/ipta.2010.5586811 dblp:conf/ipta/StojmenovicMN10 fatcat:bcufjzudvvccleil26hzw6rywm

Pulvinar Sign, Stroke and Their Relationship with Fabry Disease: A Systematic Review and Metanalysis

Juan Fernando Ortíz, María Belén Solís, Syed Saad Ali, Mahika Khurana, Juan Andrés Moncayo, Nishel Yogesh Kothari, Mateo Alzamora, Ahmed Eissa-Garces, Ghanshyam Patel, Gustavo Andrés Monteros, Meghdeep Sen, Jonathan Quiñonez
2022 Neurology International  
Fabry disease (FD) is the second most common lysosomal storage disorder. This disorder affects multiple systems that include the cardiac, renal, and nervous system. The pulvinar sign (PS) is a relatively common sign seen in patients with FD. The PS is a bilateral, symmetrical pulvinar high signal relative to the signal intensity seen on unenhanced T1-weighted brain MR imaging. Methods: We conducted a systematic review with metanalysis to analyze the pool prevalence of the disorder. We used the
more » ... oose Guidelines and PRISMA Protocol for this systematic review and Robins 1 to access the BIAS of the study. To analyze the pool prevalence, we used "Open Meta-Analysis" software for analyzing the study. We used "Review Manager 5.4" to analyze the odds ratio between patients with and without the PS and patients with and without stroke among patients with FD. Results: We gather 12 studies from 2003 to 2021 for the analysis of this study. The pool prevalence of the study was 0.146 (0.076–0.217) (62/385 cases) with a 95% CI (0.0945–0.415) (p < 0.01). The prevalence was much higher in men (59 cases) than in women (3 cases). There was no relationship between the pulvinar sign and patients with stroke among patients with Fabry disease. Odds ratio 1.97 95% CI (0.35–11.21), p = 0.44; Tau2 = 0.77. There seems to be a correlation with renal failure (RF), but there were very few studies to conduct a metanalysis with RF. Conclusions: The prevalence of the PS among all studies was 23.9%; the prevalence of this sign is higher among males. We found that FD patients who had strokes did not have higher odds of presenting with the Pulvinar Sign than the FD patients who did not suffer a stroke. Patients with renal failure and FD seem to have a higher tendency to have the PS, but there were not enough studies to analyze that theory. Overall, we think the pulvinar sign has a poor prognostic value in patients with Fabry's disease.
doi:10.3390/neurolint14020041 pmid:35736622 pmcid:PMC9229505 fatcat:htrzq6dly5fhlm5iudibcu3bd4

Robust line extraction based on repeated segment directions on image contours

Andres Solis Montero, Amiya Nayak, Milos Stojmenovic, Nejib Zaguia
2009 2009 IEEE Symposium on Computational Intelligence for Security and Defense Applications  
This paper describes a new line segment detection and extraction algorithm for computer vision, image segmentation, and shape recognition applications. This is an important pre processing step in detecting, recognizing and classifying military hardware in images. This algorithm uses a compilation of different image processing steps such as normalization, Gaussian smooth, thresholding, and Laplace edge detection to extract edge contours from colour input images. Contours of each connected
more » ... nt are divided into short segments, which are classified by their orientation into nine discrete categories. Straight lines are recognized as the minimal number of such consecutive short segments with the same direction. This solution gives us a surprisingly more accurate, faster and simpler answer with fewer parameters than the widely used Hough Transform algorithm for detecting lines segments among any orientation and location inside images. Its easy implementation, simplicity, speed, the ability to divide an edge into straight line segments using the actual morphology of objects, inclusion of endpoint information, and the use of the OpenCV library are key features and advantages of this solution procedure. The algorithm was tested on several simple shape images as well as real pictures giving more accuracy than the actual procedures based in Hough Transform. This line detection algorithm is robust to image transformations such as rotation, scaling and translation, and to the selection of parameter values.
doi:10.1109/cisda.2009.5356556 dblp:conf/cisda/MonteroNSZ09 fatcat:2jthmwq3u5fftloengmdhpk6la

Catalytic Cracking of Heavy Crude Oil over Iron-Based Catalyst Obtained from Galvanic Industry Wastes

Estefanía Villamarin-Barriga, Jéssica Canacuán, Pablo Londoño-Larrea, Hugo Solís, Andrés De La Rosa, Juan F. Saldarriaga, Carolina Montero
2020 Catalysts  
Sewage sludge from the galvanic industry represents a problem to the environment, due to its high metal content that makes it a hazardous waste and must be treated or disposed of properly. This study aimed to evaluate the sludge from three galvanic industries and determine its possible use as catalysts for the synthesis of materials. Catalyst was obtained from a thermal process based on dried between 100–120 °C and calcination of sludges between 400 to 700 °C. The physical–chemical properties
more » ... the catalyst were analyzed by several techniques as physisorption of N2 and chemisorption of CO of the material. Catalytic activity was analyzed by thermogravimetric analysis of a thermo-catalytic decomposition of crude oil. The best conditions for catalyst synthesis were calcination between 400 and 500 °C, the temperature of reduction between 750 and 850 °C for 15 min. The catalytic material had mainly Fe as active phase and the specific surface between 17.68–96.15 m2·g−1, the catalysts promote around 6% more weight-loss of crude oil in the thermal decomposition compared with assays without the catalyst. The results show that the residual sludge of galvanic industries after thermal treatment can be used as catalytic materials due to the easiness of synthesis procedures required, the low E-factor obtained and the recycling of industrial waste promoted.
doi:10.3390/catal10070736 fatcat:j3qneishyvhofdwsfr2m5cjaia

A General Framework for Fast 3D Object Detection and Localization Using an Uncalibrated Camera

Andres Solis Montero, Jochen Lang, Robert Laganiere
2015 2015 IEEE Winter Conference on Applications of Computer Vision  
In this paper, we present a real-time approach for 3D object detection using a single, mobile and uncalibrated camera. We develop our algorithm using a feature-based method based on two novel naive Bayes classifiers for viewpoint and feature matching. Our algorithm exploits the specific structure of various binary descriptors in order to boost feature matching by conserving descriptor properties (e.g., rotational and scale invariance, robustness to illumination variations and real-time
more » ... ce). Unlike state-of-the-art methods, our novel naive classifiers only require a database with a small memory footprint because we store efficiently encoded features. In addition, we also improve the indexing scheme to speed up the matching process. Because our database is built from powerful descriptors, only a few images need to be 'learned' and constructing a database for a new object is highly efficient.
doi:10.1109/wacv.2015.122 dblp:conf/wacv/MonteroLL15 fatcat:w5z62pk5und65naxc26xvwr5bq

Severity Scores in COVID-19 Pneumonia: a Multicenter, Retrospective, Cohort Study

Arturo Artero, Manuel Madrazo, Mar Fernández-Garcés, Antonio Muiño Miguez, Andrés González García, Anxela Crestelo Vieitez, Elena García Guijarro, Eva María Fonseca Aizpuru, Miriam García Gómez, María Areses Manrique, Carmen Martinez Cilleros, María Del Pilar Fidalgo Moreno (+14 others)
2021 Journal of general internal medicine  
Identification of patients on admission to hospital with coronavirus infectious disease 2019 (COVID-19) pneumonia who can develop poor outcomes has not yet been comprehensively assessed. To compare severity scores used for community-acquired pneumonia to identify high-risk patients with COVID-19 pneumonia. PSI, CURB-65, qSOFA, and MuLBSTA, a new score for viral pneumonia, were calculated on admission to hospital to identify high-risk patients for in-hospital mortality, admission to an intensive
more » ... care unit (ICU), or use of mechanical ventilation. Area under receiver operating characteristics curve (AUROC), sensitivity, and specificity for each score were determined and AUROC was compared among them. Patients with COVID-19 pneumonia included in the SEMI-COVID-19 Network. We examined 10,238 patients with COVID-19. Mean age of patients was 66.6 years and 57.9% were males. The most common comorbidities were as follows: hypertension (49.2%), diabetes (18.8%), and chronic obstructive pulmonary disease (12.8%). Acute respiratory distress syndrome (34.7%) and acute kidney injury (13.9%) were the most common complications. In-hospital mortality was 20.9%. PSI and CURB-65 showed the highest AUROC (0.835 and 0.825, respectively). qSOFA and MuLBSTA had a lower AUROC (0.728 and 0.715, respectively). qSOFA was the most specific score (specificity 95.7%) albeit its sensitivity was only 26.2%. PSI had the highest sensitivity (84.1%) and a specificity of 72.2%. PSI and CURB-65, specific severity scores for pneumonia, were better than qSOFA and MuLBSTA at predicting mortality in patients with COVID-19 pneumonia. Additionally, qSOFA, the simplest score to perform, was the most specific albeit the least sensitive.
doi:10.1007/s11606-021-06626-7 pmid:33575909 fatcat:2drbbyomx5bxvfb6xmxbnys2mm

Association of Hypertension with All-Cause Mortality among Hospitalized Patients with COVID-19

Enrique Rodilla, Alberto Saura, Iratxe Jiménez, Andrea Mendizábal, Araceli Pineda-Cantero, Elizabeth Lorenzo-Hernández, Maria del Pilar Fidalgo-Montero, Joaquín Fernandez López-Cuervo, Ricardo Gil-Sánchez, Elisa Rabadán-Pejenaute, Lucy Abella-Vázquez, Vicente Giner-Galvañ (+13 others)
2020 Journal of Clinical Medicine  
It is unclear to which extent the higher mortality associated with hypertension in the coronavirus disease (COVID-19) is due to its increased prevalence among older patients or to specific mechanisms. Cross-sectional, observational, retrospective multicenter study, analyzing 12226 patients who required hospital admission in 150 Spanish centers included in the nationwide SEMI-COVID-19 Network. We compared the clinical characteristics of survivors versus non-survivors. The mean age of the study
more » ... pulation was 67.5 ± 16.1 years, 42.6% were women. Overall, 2630 (21.5%) subjects died. The most common comorbidity was hypertension (50.9%) followed by diabetes (19.1%), and atrial fibrillation (11.2%). Multivariate analysis showed that after adjusting for gender (males, OR: 1.5, p = 0.0001), age tertiles (second and third tertiles, OR: 2.0 and 4.7, p = 0.0001), and Charlson Comorbidity Index scores (second and third tertiles, OR: 4.7 and 8.1, p = 0.0001), hypertension was significantly predictive of all-cause mortality when this comorbidity was treated with angiotensin-converting enzyme inhibitors (ACEIs) (OR: 1.6, p = 0.002) or other than renin-angiotensin-aldosterone blockers (OR: 1.3, p = 0.001) or angiotensin II receptor blockers (ARBs) (OR: 1.2, p = 0.035). The preexisting condition of hypertension had an independent prognostic value for all-cause mortality in patients with COVID-19 who required hospitalization. ARBs showed a lower risk of lethality in hypertensive patients than other antihypertensive drugs.
doi:10.3390/jcm9103136 pmid:32998337 fatcat:vsmhv2bvtjfyhli7tnrzjgye3q

Efficient Feature Extraction for Shape Analysis, Object Detection and Tracking

Andres Solis Montero, Université D'Ottawa / University Of Ottawa, Université D'Ottawa / University Of Ottawa
2016
During the course of this thesis, two scenarios are considered. In the first one, we contribute to feature extraction algorithms. In the second one, we use features to improve object detection solutions and localization. The two scenarios give rise to into four thesis sub-goals. First, we present a new shape skeleton pruning algorithm based on contour approximation and the integer medial axis. The algorithm effectively removes unwanted branches, conserves the connectivity of the skeleton and
more » ... pects the topological properties of the shape. The algorithm is robust to significant boundary noise and to rigid shape transformations. It is fast and easy to implement. While shape-based solutions via boundary and skeleton analysis are viable solutions to object detection, keypoint features are important for textured object detection. Therefore, we present a keypoint featurebased planar object detection framework for vision-based localization. We demonstrate that our framework is robust against illumination changes, perspective distortion, motion blur, and occlusions. We increase robustness of the localization scheme in cluttered environments and decrease false detection of targets. We present an off-line target evaluation strategy and a scheme to improve pose. Third, we extend planar object detection to a real-time approach for 3D object detection using a mobile and uncalibrated camera. We develop our algorithm based on two novel naive Bayes classifiers for viewpoint and feature matching that improve performance and decrease memory usage. Our algorithm exploits the specific structure of various binary descriptors in order to boost feature matching by conserving descriptor properties. Our novel naive classifiers require a database with a small memory footprint because we only store efficiently encoded features. We improve the feature-indexing scheme to speed up the matching process creating a highly efficient database for objects. Finally, we present a model-free long-term tracking algorithm based on the Kernelized Corre [...]
doi:10.20381/ruor-6105 fatcat:izrpsnlshbbqjhgtdvkcplf3ga

Towards Feature Detection based on Morphology of Objects on Image

Andres Solis Montero, Université D'Ottawa / University Of Ottawa, Université D'Ottawa / University Of Ottawa
2013
This thesis describes a new line segment detection and extraction algorithm for computer vision, image segmentation, and shape recognition applications. This algorithm uses a compilation of different image processing techniques such as normalization, Gaussian smooth, automatic threshold, and Laplace edge detection to extract edge contours from color input images. Contours of each connected component are divided into short segments, which are classified by their orientation into about ten
more » ... e categories. Straight lines are recognized as the minimal number of such consecutive short segments with the same direction. This solution indeed gives us more precise line segments (including line endpoints) and requires a shorter time than the widely used Hough Transform algorithm for detecting line segments given any orientation and location inside an image. Its easy implementation, simplicity, parameter minimization, speed, ability to split an edge into straight line segments using the actual morphology of objects, accuracy and the use of OpenCV library are key features and advantages of the proposed approach. The algorithm was tested on several simple shape images as well as on real pictures, yielding a more accurate resemblance of straight lines in accordance with the human perception of line taxonomy. The line detection algorithm introduced here requires few parameters and is robust to standard image transformations such as rotation, scaling and translation. Furthermore, some of these parameters are selected by automatic unsupervised methods, thus improving the expected algorithm outcome in terms of the stated problem. Several experimental results are presented to support the validity of the algorithm.
doi:10.20381/ruor-19332 fatcat:uywnya5b5ber3bdkrrlhcyx7me
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