Search results for " processing"
showing 10 items of 7549 documents
A completely automated CAD system for mass detection in a large mammographic database.
2006
Mass localization plays a crucial role in computer-aided detection (CAD) systems for the classification of suspicious regions in mammograms. In this article we present a completely automated classification system for the detection of masses in digitized mammographic images. The tool system we discuss consists in three processing levels: (a) Image segmentation for the localization of regions of interest (ROIs). This step relies on an iterative dynamical threshold algorithm able to select iso-intensity closed contours around gray level maxima of the mammogram. (b) ROI characterization by means of textural features computed from the gray tone spatial dependence matrix (GTSDM), containing secon…
Fuzzy technique for microcalcifications clustering in digital mammograms
2012
Abstract Background Mammography has established itself as the most efficient technique for the identification of the pathological breast lesions. Among the various types of lesions, microcalcifications are the most difficult to identify since they are quite small (0.1-1.0 mm) and often poorly contrasted against an images background. Within this context, the Computer Aided Detection (CAD) systems could turn out to be very useful in breast cancer control. Methods In this paper we present a potentially powerful microcalcifications cluster enhancement method applicable to digital mammograms. The segmentation phase employs a form filter, obtained from LoG filter, to overcome the dependence from …
Exudate-based diabetic macular edema detection in fundus images using publicly available datasets
2010
International audience; Diabetic macular edema (DME) is a common vision threatening complication of diabetic retinopathy. In a large scale screening environment DME can be assessed by detecting exudates (a type of bright lesions) in fundus images. In this work, we introduce a new methodology for diagnosis of DME using a novel set of features based on colour, wavelet decomposition and automatic lesion segmentation. These features are employed to train a classifier able to automatically diagnose DME through the presence of exudation. We present a new publicly available dataset with ground-truth data containing 169 patients from various ethnic groups and levels of DME. This and other two publi…
Multidimensionālu attēlu spektrālo joslu ekvivalentas redukcijas pieejas objektu klasifikācijai
2019
Darbs veltīts multidimensionālu attēlu apstrādes problēmām, kas saistītas ar šo attēlu spektrālo joslu izvēli un pikseļu klasifikāciju. Izstrādātas jaunas, relatīvi vienkāršas un vispārīgas nevadītās: EMCR, EXCR, ESCR, ECBG un vadītā: XECT joslu izvēles procedūras informatīvu spektrālo joslu komplektu noteikšanai hiperspektrālajos attēlos. Informativitāte tika pārbaudīta ar Beijesa, k-NN, SVM, ELM un citiem klasifikatoriem, no kuriem augstāku klasifikācijas precizitāti sniedza SVM, izmantojot ECBG procedūru. Atslēgvārdi: hiperspketrālu attēlu apstrāde, spektrālo joslu izvēle, hiperspektrālu attēlu klasifikācija, tālizpēte
Strukturētu datu grafu vizualizācija virtuālā realitātē kā rīks lai asistētu noziegumu digitālā izmeklēšanā
2022
Maģistra darbā „Strukturētu datu grafu vizualizācija virtuālā realitātē kā rīks lai asistētu noziegumu digitālā izmeklēšanā” tiek apskatīti pētījumi par datu apstrādes metodēm digitālā izmeklēšanā un datu attēlošanas paņēmieniem. Darba mērķis ir, balstoties uz pētījumu analīzi, izstrādāt reālus un funkcionējošus, divus savstarpēji atkarīgus, rīku prototipus, kas veiktu kriminālprocesa laikā izgūto datu apstrādi, izveidojot starp tām saistības, vienā un veiktu skaidru un saprotamu apstrādāto datu attēlošanu otrā.
Optical calibration of a multispectral imaging system based on interference filters
2005
We present a new approach to optically calibrate a multispectral imaging system based on interference filters. Such a system typically suffers from some blurring of its channel images. Because the effectiveness of spectrum reconstruction depends heavily on the quality of the acquired channel images, and because this blurring negatively affects them, a method for deblurring and denoising them is required. The blur is modeled as a uniform intensity distribution within a circular disk. It allows us to characterize, quantitatively, the degradation for each channel image. In terms of global reduction of the blur, it consists of the choice of the best channel for the focus adjustment according to…
Iterative Symmetry Detection: Shrinking vs. Decimating Patterns
2005
This paper introduces a new mechanism that consists of applying a symmetry operator on an iteratively transformed version of the input image. The nature of the transformation characterizes the operator. Here, we consider the Object Symmetry Transform combined with the morphological operator erosion and the pyramid decimation respectively. The derived operators have been applied on both binary and gray levels images, comparing their ability to grasp the internal structure of a digital object. We present some experiments to evaluate their performances and check them for result quality versus computing complexity.
The effects of associative and semantic priming in the lexical decision task.
2001
Four lexical decision experiments were conducted to examine under which conditions automatic semantic priming effects can be obtained. Experiments 1 and 2 analyzed associative/semantic effects at several very short stimulus-onset asynchronies (SOAs), whereas Experiments 3 and 4 used a single-presentation paradigm at two response-stimulus intervals (RSIs). Experiment 1 tested associatively related pairs from three semantic categories (synonyms, antonyms, and category coordinates). The results showed reliable associative priming effects at all SOAs. In addition, the correlation between associative strength and magnitude of priming was significant only at the shortest SOA (66 ms). When prime-t…
Essential Enabling Technologies
2016
The previous chapter contained presentations of several relevant collaboration methods. Section 3.1 indicated that the evolution in e-collaboration was associated with a number of technological breakthroughs.
Building energy demand assessment through heating degree days: the importance of a climatic dataset
2019
Abstract The weather is one of the main factors to consider when designing a building because it represents the most important boundary condition to affect the dynamic behaviour of the building. In the literature, many studies use the degree day to predict building energy demand. However, linking the results obtained from a generic building simulation tool with defined degree days, will not give reliable energy evaluation. The goal of this study is to demonstrate that the assessment of building energy demand through the use of the degree day is correct only if the determination of the climate index is a function of the same weather data. The relationship between Heating Degree-Day and heati…