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Author | Jaume Garcia; Albert Andaluz; Debora Gil; Francesc Carreras | ||||
Title | Decoupled External Forces in a Predictor-Corrector Segmentation Scheme for LV Contours in Tagged MR Images | Type | Conference Article | ||
Year | 2010 | Publication | 32nd Annual International Conference of the IEEE Engineering in Medicine and Biology Society | Abbreviated Journal | |
Volume | Issue | Pages | 4805-4808 | ||
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Abstract | Computation of functional regional scores requires proper identification of LV contours. On one hand, manual segmentation is robust, but it is time consuming and requires high expertise. On the other hand, the tag pattern in TMR sequences is a problem for automatic segmentation of LV boundaries. We propose a segmentation method based on a predictorcorrector (Active Contours – Shape Models) scheme. Special stress is put in the definition of the AC external forces. First, we introduce a semantic description of the LV that discriminates myocardial tissue by using texture and motion descriptors. Second, in order to ensure convergence regardless of the initial contour, the external energy is decoupled according to the orientation of the edges in the image potential. We have validated the model in terms of error in segmented contours and accuracy of regional clinical scores. | ||||
Address | Buenos Aires (Argentina) | ||||
Corporate Author | IEEE EMB | Thesis | |||
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ISSN | 1557-170X | ISBN | 978-1-4244-4123-5 | Medium | |
Area | Expedition | Conference | EMBC | ||
Notes | IAM | Approved | no | ||
Call Number | IAM @ iam @ GAG2010 | Serial | 1514 | ||
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Author | Patricia Marquez | ||||
Title | Conditions Ensuring Accuracy of Local Optical Flow Schemes | Type | Report | ||
Year | 2010 | Publication | CVC Tehcnical Report | Abbreviated Journal | |
Volume | 157 | Issue | Pages | ||
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Abstract | Accurate computation of optical flow is a key-point in many image processing fields. Detection of anomalous and unpredicted agents (such as pedestrians, bikers or cars) in urban scenes or pathology discrimination in medical imaging sequences, to mention just a two. The above kinds sequences present two main difficulties for standard optical flow techniques. On one hand, variability in acquisition conditions (illuminance, medical imaging modality, ...) force an alterantive representation for images fulfilling the britghtness constancy constrain. On the hand, current variational schemes produce oversmoothed fields unable to properly model discontinuous behaviours such as collisions or functionless pathological areas. This master project explores the abilities and limitations of local and global optical flow approaches. The master student will put especial emphasis in the theoretical grounds behind in order to design a variational framework combining the theoretical advantages of the considered techniques. In particular an optical flow based on Gabor phase tracking (developed in the group for medical imaging) will be generalized to urban scenes. | ||||
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Corporate Author | Thesis | Master's thesis | |||
Publisher | Place of Publication | Bellaterra 08193, Barcelona, Spain | Editor | ||
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Notes | IAM; | Approved | no | ||
Call Number | IAM @ iam @ Mar2010 | Serial | 1582 | ||
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Author | Maurizio Mencuccini; Jordi Martinez-Vilalta; Josep Piñol; Lasse Loepfe; Mireia Burnat ; Xavier Alvarez; Juan Camacho; Debora Gil | ||||
Title | A quantitative and statistically robust method for the determination of xylem conduit spatial distribution | Type | Journal Article | ||
Year | 2010 | Publication | American Journal of Botany | Abbreviated Journal | AJB |
Volume | 97 | Issue | 8 | Pages | 1247-1259 |
Keywords | Geyer; hydraulic conductivity; point pattern analysis; Ripley; Spatstat; vessel clusters; xylem anatomy; xylem network | ||||
Abstract | Premise of the study: Because of their limited length, xylem conduits need to connect to each other to maintain water transport from roots to leaves. Conduit spatial distribution in a cross section plays an important role in aiding this connectivity. While indices of conduit spatial distribution already exist, they are not well defined statistically. * Methods: We used point pattern analysis to derive new spatial indices. One hundred and five cross-sectional images from different species were transformed into binary images. The resulting point patterns, based on the locations of the conduit centers-of-area, were analyzed to determine whether they departed from randomness. Conduit distribution was then modeled using a spatially explicit stochastic model. * Key results: The presence of conduit randomness, uniformity, or aggregation depended on the spatial scale of the analysis. The large majority of the images showed patterns significantly different from randomness at least at one spatial scale. A strong phylogenetic signal was detected in the spatial variables. * Conclusions: Conduit spatial arrangement has been largely conserved during evolution, especially at small spatial scales. Species in which conduits were aggregated in clusters had a lower conduit density compared to those with uniform distribution. Statistically sound spatial indices must be employed as an aid in the characterization of distributional patterns across species and in models of xylem water transport. Point pattern analysis is a very useful tool in identifying spatial patterns. | ||||
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Notes | IAM; | Approved | no | ||
Call Number | IAM @ iam @ MMG2010 | Serial | 1623 | ||
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Author | Ferran Poveda; Jaume Garcia; Enric Marti; Debora Gil | ||||
Title | Validation of the myocardial architecture in DT-MRI tractography | Type | Conference Article | ||
Year | 2010 | Publication | Medical Image Computing in Catalunya: Graduate Student Workshop | Abbreviated Journal | |
Volume | Issue | Pages | 29-30 | ||
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Abstract | Deep understanding of myocardial structure may help to link form and funcion of the heart unraveling crucial knowledge for medical and surgical clinical procedures and studies. In this work we introduce two visualization techniques based on DT-MRI streamlining able to decipher interesting properties of the architectural organization of the heart. | ||||
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Publisher | Place of Publication | Girona (Spain) | Editor | ||
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Area | Expedition | Conference | MICCAT | ||
Notes | IAM | Approved | no | ||
Call Number | IAM @ iam @ PGM2010 | Serial | 1626 | ||
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Author | Sergio Vera | ||||
Title | Finger joint modelling from hand X-ray images for assessing rheumatoid arthritis | Type | Report | ||
Year | 2010 | Publication | CVC Technical Report | Abbreviated Journal | |
Volume | 164 | Issue | Pages | ||
Keywords | Rheumatoid arthritis; joint detection; X-ray; Van der Heijde score | ||||
Abstract | Rheumatoid arthritis is an autoimmune, systemic, inflammatory disorder that mainly af- fects bone joints. While there is no cure for this disease, continuous advances on palliative treatments require frequent verification of patient’s illness evolution. Such evolution is mea- sured through several available semi-quantitative methods that require evaluation of hand and foot X-ray images. Accurate assessment is a time consuming task that requires highly trained personnel. This hinders a generalized use in clinical practice for early diagnose and disease follow-up. In the context of the automatization of such evaluation methods we present a method for detection and characterization of finger joints in hand radiography images. Several measures for assessing the reduction of joint space width are proposed. We compare for the first time such measures to the Van der Heijde score, the gold standard method for rheumatoid arthritis assessment. The proposed method outperforms existing strategies with a detection rate above 95%. Our comparison to Van der Heijde index shows a promising correlation that encourages further research. | ||||
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Corporate Author | Thesis | Master's thesis | |||
Publisher | Place of Publication | Bellaterra 01893, Barcelona, Spain | Editor | ||
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Notes | IAM | Approved | no | ||
Call Number | IAM @ iam @ Ver2010 | Serial | 1661 | ||
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Author | Fernando Vilariño; Panagiota Spyridonos; Petia Radeva; Jordi Vitria; Fernando Azpiroz; Juan Malagelada | ||||
Title | Method for automatic classification of in vivo images | Type | Patent | ||
Year | 2010 | Publication | US 2010/0046816 | Abbreviated Journal | |
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Abstract | A method for automatically detecting a post-duodenal boundary in an image stream of the gastrointestinal (GI) tract. The image stream is sampled to obtain a reduced set of images for processing. The reduced set of images is filtered to remove non-valid frames or non-valid portions of frames, thereby generating a filtered set of valid images. A polar representation of the valid images is generated. Textural features of the polar representation are processed to detect the post-duodenal boundary of the GI tract. | ||||
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Area | 800 | Expedition | Conference | ||
Notes | MV;OR;MILAB;SIAI | Approved | no | ||
Call Number | IAM @ iam @ VSR2010 | Serial | 1702 | ||
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Author | Miguel Angel Bautista; Sergio Escalera; Xavier Baro; Oriol Pujol; Jordi Vitria; Petia Radeva | ||||
Title | Compact Evolutive Design of Error-Correcting Output Codes. Supervised and Unsupervised Ensemble Methods and Applications | Type | Conference Article | ||
Year | 2010 | Publication | European Conference on Machine Learning | Abbreviated Journal | |
Volume | I | Issue | Pages | 119-128 | |
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Area | Expedition | Conference | ECML | ||
Notes | MILAB; OR;HUPBA;MV | Approved | no | ||
Call Number | Admin @ si @ BEB2010 | Serial | 1775 | ||
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Author | Carolina Malagelada; F.De Lorio; Fernando Azpiroz; Santiago Segui; Petia Radeva; Anna Accarino; J.Santos; Juan R. Malagelada | ||||
Title | Intestinal Dysmotility in Patients with Functional Intestinal Disorders Demonstrated by Computer Vision Analysis of Capsule Endoscopy Images | Type | Conference Article | ||
Year | 2010 | Publication | 18th United European Gastroenterology Week | Abbreviated Journal | |
Volume | 56 | Issue | 3 | Pages | A19-20 |
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Address | Barcelona | ||||
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Area | Expedition | Conference | UEGW | ||
Notes | MILAB | Approved | no | ||
Call Number | Admin @ si @ MLA2010 | Serial | 1779 | ||
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Author | Sophie Wuerger; Kaida Xiao; Chenyang Fu; Dimosthenis Karatzas | ||||
Title | Colour-opponent mechanisms are not affected by age-related chromatic sensitivity changes | Type | Journal Article | ||
Year | 2010 | Publication | Ophthalmic and Physiological Optics | Abbreviated Journal | OPO |
Volume | 30 | Issue | 5 | Pages | 635-659 |
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Abstract | The purpose of this study was to assess whether age-related chromatic sensitivity changes are associated with corresponding changes in hue perception in a large sample of colour-normal observers over a wide age range (n = 185; age range: 18-75 years). In these observers we determined both the sensitivity along the protan, deutan and tritan line; and settings for the four unique hues, from which the characteristics of the higher-order colour mechanisms can be derived. We found a significant decrease in chromatic sensitivity due to ageing, in particular along the tritan line. From the unique hue settings we derived the cone weightings associated with the colour mechanisms that are at equilibrium for the four unique hues. We found that the relative cone weightings (w(L) /w(M) and w(L) /w(S)) associated with the unique hues were independent of age. Our results are consistent with previous findings that the unique hues are rather constant with age while chromatic sensitivity declines. They also provide evidence in favour of the hypothesis that higher-order colour mechanisms are equipped with flexible cone weightings, as opposed to fixed weights. The mechanism underlying this compensation is still poorly understood. | ||||
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Notes | DAG; IF: 1.259 | Approved | no | ||
Call Number | Admin @ si @ WXF2010 | Serial | 1826 | ||
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Author | Albert Ali Salah; E. Pauwels; R. Tavenard; Theo Gevers | ||||
Title | T-Patterns Revisited: Mining for Temporal Patterns in Sensor Data | Type | Journal Article | ||
Year | 2010 | Publication | Sensors | Abbreviated Journal | SENS |
Volume | 10 | Issue | 8 | Pages | 7496-7513 |
Keywords | sensor networks; temporal pattern extraction; T-patterns; Lempel-Ziv; Gaussian mixture model; MERL motion data | ||||
Abstract | The trend to use large amounts of simple sensors as opposed to a few complex sensors to monitor places and systems creates a need for temporal pattern mining algorithms to work on such data. The methods that try to discover re-usable and interpretable patterns in temporal event data have several shortcomings. We contrast several recent approaches to the problem, and extend the T-Pattern algorithm, which was previously applied for detection of sequential patterns in behavioural sciences. The temporal complexity of the T-pattern approach is prohibitive in the scenarios we consider. We remedy this with a statistical model to obtain a fast and robust algorithm to find patterns in temporal data. We test our algorithm on a recent database collected with passive infrared sensors with millions of events. | ||||
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Notes | ALTRES;ISE | Approved | no | ||
Call Number | Admin @ si @ SPT2010 | Serial | 1845 | ||
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Author | Koen E.A. van de Sande; Theo Gevers; C.G.M. Snoek | ||||
Title | Evaluating Color Descriptors for Object and Scene Recognition | Type | Journal Article | ||
Year | 2010 | Publication | IEEE Transaction on Pattern Analysis and Machine Intelligence | Abbreviated Journal | TPAMI |
Volume | 32 | Issue | 9 | Pages | 1582 - 1596 |
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Abstract | Impact factor: 5.308
Image category recognition is important to access visual information on the level of objects and scene types. So far, intensity-based descriptors have been widely used for feature extraction at salient points. To increase illumination invariance and discriminative power, color descriptors have been proposed. Because many different descriptors exist, a structured overview is required of color invariant descriptors in the context of image category recognition. Therefore, this paper studies the invariance properties and the distinctiveness of color descriptors (software to compute the color descriptors from this paper is available from http://www.colordescriptors.com) in a structured way. The analytical invariance properties of color descriptors are explored, using a taxonomy based on invariance properties with respect to photometric transformations, and tested experimentally using a data set with known illumination conditions. In addition, the distinctiveness of color descriptors is assessed experimentally using two benchmarks, one from the image domain and one from the video domain. From the theoretical and experimental results, it can be derived that invariance to light intensity changes and light color changes affects category recognition. The results further reveal that, for light intensity shifts, the usefulness of invariance is category-specific. Overall, when choosing a single descriptor and no prior knowledge about the data set and object and scene categories is available, the OpponentSIFT is recommended. Furthermore, a combined set of color descriptors outperforms intensity-based SIFT and improves category recognition by 8 percent on the PASCAL VOC 2007 and by 7 percent on the Mediamill Challenge. |
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ISSN | 0162-8828 | ISBN | Medium | ||
Area | Expedition | Conference | |||
Notes | ALTRES;ISE | Approved | no | ||
Call Number | Admin @ si @ SGS2010 | Serial | 1846 | ||
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Author | Oriol Ramos Terrades; Alejandro Hector Toselli; Nicolas Serrano; Veronica Romero; Enrique Vidal; Alfons Juan | ||||
Title | Interactive layout analysis and transcription systems for historic handwritten documents | Type | Conference Article | ||
Year | 2010 | Publication | 10th ACM Symposium on Document Engineering | Abbreviated Journal | |
Volume | Issue | Pages | 219–222 | ||
Keywords | Handwriting recognition; Interactive predictive processing; Partial supervision; Interactive layout analysis | ||||
Abstract | The amount of digitized legacy documents has been rising dramatically over the last years due mainly to the increasing number of on-line digital libraries publishing this kind of documents, waiting to be classified and finally transcribed into a textual electronic format (such as ASCII or PDF). Nevertheless, most of the available fully-automatic applications addressing this task are far from being perfect and heavy and inefficient human intervention is often required to check and correct the results of such systems. In contrast, multimodal interactive-predictive approaches may allow the users to participate in the process helping the system to improve the overall performance. With this in mind, two sets of recent advances are introduced in this work: a novel interactive method for text block detection and two multimodal interactive handwritten text transcription systems which use active learning and interactive-predictive technologies in the recognition process. | ||||
Address | Manchester, United Kingdom | ||||
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Area | Expedition | Conference | ACM | ||
Notes | DAG | Approved | no | ||
Call Number | Admin @ si @RTS2010 | Serial | 1857 | ||
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Author | N. Serrano; L. Tarazon; D. Perez; Oriol Ramos Terrades; S. Juan | ||||
Title | The GIDOC Prototype | Type | Conference Article | ||
Year | 2010 | Publication | 10th International Workshop on Pattern Recognition in Information Systems | Abbreviated Journal | |
Volume | Issue | Pages | 82-89 | ||
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Abstract | Transcription of handwritten text in (old) documents is an important, time-consuming task for digital libraries. It might be carried out by first processing all document images off-line, and then manually supervising system transcriptions to edit incorrect parts. However, current techniques for automatic page layout analysis, text line detection and handwriting recognition are still far from perfect, and thus post-editing system output is not clearly better than simply ignoring it.
A more effective approach to transcribe old text documents is to follow an interactive- predictive paradigm in which both, the system is guided by the user, and the user is assisted by the system to complete the transcription task as efficiently as possible. Following this approach, a system prototype called GIDOC (Gimp-based Interactive transcription of old text DOCuments) has been developed to provide user-friendly, integrated support for interactive-predictive layout analysis, line detection and handwriting transcription. GIDOC is designed to work with (large) collections of homogeneous documents, that is, of similar structure and writing styles. They are annotated sequentially, by (par- tially) supervising hypotheses drawn from statistical models that are constantly updated with an increasing number of available annotated documents. And this is done at different annotation levels. For instance, at the level of page layout analysis, GIDOC uses a novel text block detection method in which conventional, memoryless techniques are improved with a “history” model of text block positions. Similarly, at the level of text line image transcription, GIDOC includes a handwriting recognizer which is steadily improved with a growing number of (partially) supervised transcriptions. |
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Address | Funchal, Portugal | ||||
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ISSN | ISBN | 978-989-8425-14-0 | Medium | ||
Area | Expedition | Conference | PRIS | ||
Notes | DAG | Approved | no | ||
Call Number | Admin @ si @ STP2010 | Serial | 1868 | ||
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Author | Monica Piñol | ||||
Title | Adaptative Vocabulary Tree for Image Classification using Reinforcement Learning | Type | Report | ||
Year | 2010 | Publication | CVC Technical Report | Abbreviated Journal | |
Volume | 162 | Issue | Pages | ||
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Address | Bellaterra (Barcelona) | ||||
Corporate Author | Computer Vision Center | Thesis | Master's thesis | ||
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Notes | ADAS | Approved | no | ||
Call Number | Admin @ si @ Piñ2010 | Serial | 1936 | ||
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Author | Joan Arnedo-Moreno; Agata Lapedriza | ||||
Title | Visualizing key authenticity: turning your face into your public key | Type | Conference Article | ||
Year | 2010 | Publication | 6th China International Conference on Information Security and Cryptology | Abbreviated Journal | |
Volume | Issue | Pages | 605-618 | ||
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Abstract | Biometric information has become a technology complementary to cryptography, allowing to conveniently manage cryptographic data. Two important needs are ful lled: rst of all, making such data always readily available, and additionally, making its legitimate owner easily identi able. In this work we propose a signature system which integrates face recognition biometrics with and identity-based signature scheme, so the user's face e ectively becomes his public key and system ID. Thus, other users may verify messages using photos of the claimed sender, providing a reasonable trade-o between system security and usability, as well as a much more straightforward public key authenticity and distribution process. | ||||
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Series Editor | Series Title | Abbreviated Series Title | LNCS | ||
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Area | Expedition | Conference | Inscrypt | ||
Notes | OR;MV | Approved | no | ||
Call Number | Admin @ si @ ArL2010c | Serial | 2149 | ||
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