1,721,174 research outputs found
Exploring Multimedia Applications Locality to Improve Cache Performance
No full textThis research aims to explore possible solutions to improvementof performance in multimedia processor [1]. In this context, cache memory performance plays a more and more critical role in computer systems, since the gap between processor speed and main memory speed tends to increase rather than the contrary. The integration inside the computational units of some SIMD improvements (such as Pentinm MMX, HP MAX2 or UltraSparc VIS) for improving the parallel computation on image pixels is the main answer to the heavy workloads of multimedia applications [2]. Moreover, the workload of multimedia applications [3] has a strong impact on cache memory performance, since the locality of memory references embedded in multimedia programs differs from that of traditional programs. In fact, as widely known, programs exhibit two main kind of locality: spatial and temporal. Nevertheless, as stated in [1],multimedia applications seem to present a new kind of locality,called 2D-spatial locality (i.e. there is an high probability that accessing to an address, future accesses will be in a bidimensional neighborhood of it). For this reason, standard cache memory organization achieves poorer performancewhen used for multimedia. To achieve an overall performance improvement on specialized multimedia processors, further architectural modification on memory hierarchy and on its management should be fulfilled. This could be coupled with the recent idea of associating programmable components with memory separated from the main processor, such as IRAM [4]
Very Fast Ellipse Detection for Embedded Vision Applications
No full textReal-time ellipse detection is an important yet challenging task, since the estimation of the five parameters of an ellipse requires heavy computation. This task is even more challenging when the processing must be done on a mobile device with limited computational power. The typical trade-off between accuracy, efficiency and limited resources of embedded vision programming must be accounted. In this paper we present a novel strategy for edge point selection, which allows to drastically reduce the number of edge points to be evaluated for parameters estimation, making embedded mobile vision applications feasible. Extensive results show the increased efficiency of the proposed method over state-of-the-art ellipse detectors, in synthetic and challenging real images, and in a live mobile application
METODO DI SEGMENTAZIONE BASATO SULLE CARATTERISTICHE PER SEGMENTARE UNA PLURALITA’ DI ARTICOLI DUPLICATI DISPOSTI ALLA RINFUSA E GRUPPO CHE ATTUA TALE METODO PER ALIMENTARE UNA MACCHINA CONFEZIONATRICE
No full textViene divulgato un metodo di segmentazione basato sulle caratteristiche per segmentare una pluralità di articoli duplicati (3) disposti alla rinfusa, comprendente le fasi di: acquisire un’immagine (M) di un articolo campione (30); calcolare coppie keypoint-descrittore dell’immagine (M); definire una figura identificativa (Z) sull’immagine (M); acquisire una prima immagine (I1) di una pluralità di articoli; calcolare coppie keypoint-descrittore della prima immagine (I1); eseguire il matching delle coppie keypoint-descrittore così definite; acquisire la posizione e l’orientamento relativo della figura identificativa (Z) rispetto ad una prima coppia keypoint-descrittore dell’immagine (M) avente un match con una seconda coppia keypoint-descrittore della prima immagine (I1); definire nella prima immagine (I1) una figura identificativa di proiezione come trasformazione euclidea della figura identificativa (Z) con riferimento alla prima e seconda coppia citate; applicare le due fasi precedenti ad una pluralità di coppie keypoint-descrittore dell’immagine (M) aventi un match con una coppia keypoint-descrittore della prima immagine (I1); raggruppare insieme figure identificative di proiezione aventi fra loro un prestabilito grado di sovrapposizione; definire una figura rappresentativa per ciascun gruppo di figure identificative di proiezione che è formato da un numero minimo prestabilito di figure identificative di proiezione, la quale figura rappresentativa ha la medesima forma e dimensioni di una figura identificativa di proiezione ed è scelta per stimare la posizione di un corrispondente articolo illustrato nella prima immagine (I1).Viene altresì divulgato un metodo per prelevare articoli (3) disposti alla rinfusa in una zona di accumulo di articoli (5) e per posizionare tali articoli (3) in una stazione di uscita (SU), ed un gruppo che attua tale metodo
METODO DI SEGMENTAZIONE BASATO SULLE CARATTERISTICHE PER SEGMENTARE UNA PLURALITA’ DI ARTICOLI DUPLICATI DISPOSTI ALLA RINFUSA E GRUPPO CHE ATTUA TALE METODO PER ALIMENTARE UNA MACCHINA CONFEZIONATRICE
No full textReal-time object detection and localization with SIFT-based clustering
No full textThis paper presents an innovative approach for detecting and localizing duplicate objects in pick-and-place applications under extreme conditions of occlusion, where standard appearance-based approaches are likely to be ineffective. The approach exploits SIFT keypoint extraction and mean shift clustering to partition the correspondences between the object model and the image onto different potential object instances with real-time performance. Then, the hypotheses of the object shape are validated by a projection with a fast Euclidean transform of some delimiting points onto the current image. Moreover, in order to improve the detection in the case of reflective or transparent objects, multiple object models (of both the same and different faces of the object) are used and fused together. Many measures of efficacy and efficiency are provided on random disposals of heavily-occluded objects, with a specific focus on real-time processing. Experimental results on different and challenging kinds of objects are reported
On the usefulness of object shape coding with MPEG-4
No full textThis paper reports the results of an in-depth analysis ofthe degree of usefulness of object shape coding in videocompression. In particular, MPEG-4 is used as referencestandard. The influence of different coding parameters onthe performance is deeply examined and discussions on theresults are provided. Object shape coding is compared withclassical (MPEG-2) frame-based coding both at an objectivelevel (by comparing PSNR/quality and bitrate/filesize)and at a subjective level (asking to a set of users to expresstheir opinion on overall quality, cognitive effectiveness, andwillingness to pay). In conclusion, this paper aims at answering to the question whether it is convenient to use object shape coding instead of frame-based coding or not
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