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In this article we present a self-learning system for automatic detection of surface failures on ceramic tiles. This system is based on the probabilistic neural network with radial basis. The discrete wavelet transform (DWT) is used as a preprocessing method with good feature extraction possibilities. With an automatic procedure for the production of input vectors for the neural networks training...
Aiming at the reduction of the existing digital gap between many rural and urban european areas as well as at the optimization of the rural broadband access deployment costs, several rural broadband deployment cases in the Republic of Croatia are compared in this paper. The comparison is conducted from the business and the regulatory point of view, and the possibilities of the cost-effective solutions...
In modern communication systems with video transmission as their important part, objective video quality evaluation is necessary in the QoS (quality of service) assessment. This article analyzes spatial masking effects on the visibility of compression artifacts, and consequently its importance in the digital video quality evaluation process. Luminance masking and texture masking are mechanisms referred...
Objective video quality evaluation incorporates spatial and temporal degradation effects to calculate quality grade for each video frame alone, as well as the overall quality grade for the whole sequence. Distortion visibility depends not only on the level of degradation but also on video content and viewer's preferences. Temporal pooling is a method that collapses series of frame quality scores to...
Worldwide Interoperability for Microwave Access (WiMAX) is a new wireless broadband technology based on IEEE 802.16 standard. Its radio interface enables high data transmission rates in the frequency range of 2-11 GHz and 10-66 GHz. The existing empirical models, most often used for path loss prediction, are mostly developed for frequencies below 2 GHz. This paper analyses empirical models suitability...
Efficiency of the video coding process, as well as accuracy of the objective video quality evaluation can be significantly improved by introducing the human visual system (HVS) characteristics. In this paper the usage of the foveation technique in the video quality assessment is analyzed. This technique takes into account non-uniform sampling that corresponds with the acquisition of visual information...
The H.264/AVC codec provides a superior coding efficiency and an improved network adaptation if compared to older video standards. In this paper we present experimental results obtained by the subjective and objective quality evaluation of the H.264/AVC coded video. Four objective metrics are used: peak signal-to-noise ratio (PSNR), minimum of locally averaged PSNR (local_PSNR), video quality metric...
An overview of a new scalable video coding (SVC) extension of the H.264/AVC standard is given in this paper. A performance analysis is presented for quality and spatial scalability. Influence of the inter-layer prediction and the number of scalable layers to coding efficiency is shown. Results for CGS (coarse-grain quality scalability) and MGS (medium-grain quality scalability) coding are also compared.
In this paper we have analyzed possibility of using PSNR (peak signal-to-noise ratio) locally averaged over N successive picture in a video sequence as a simple objective video quality metric. Results of PSNR averaged over different number of pictures (N) are presented and compared with results obtained with standard PSNR and another two objective metrics: VQM (video quality metric) and SSIM (structural...
Fixed Wireless Access (FWA) networks based on WiMAX technology provide efficient packet radio interface enabling high data transmission rates. The accurate prediction of path losses is a crucial element in the first step of network planning. This paper presents few empirical models suitable for path loss prediction in mobile as well as fixed wireless systems like WiMAX. Experimental measurements of...
This paper discusses methods used in different objective video quality metrics. An experimental comparison of different objective methods is also conducted. This experiment shows the importance of video content for a subjective quality evaluation not comprised well by the objective metrics used.
brief overview of H.264/AVC and MPEG-4 Part 2 standards is given in this paper with focus on differences between them. Experimental quality comparison of H.264/AVC and MPEG-2 Part 2 coded video is done for several sequences and bit rates. The codecs used in the experiment are JVT JM ver. 10.2, as implementation of H.264/AVC, andXviD ver. 1.1.0, as implementation of MPEG-4 Part 2. The peak signal-to-noise...
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