The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
This paper proposes a fast hardware friendly intra block size selection algorithm with simple gradient calculations and the bottom-up structure to solve the high computational demand of intra prediction in the latest HEVC (High Efficiency Video Coding) standard. The simulation results show that the proposed algorithm can save 57.3% encoding time in average for all-intra main case compared to the default...
As throughput of wireless technologies had improved rapidly over the last decade, handheld devices became more attractive to the end users enabling multimedia applications "on-the-move". The uptime of mobile devices depends on their battery power that is not growing at the pace of communication technologies. In this study we describe the trade-offs between the power consumption, compression...
Most recently, the low density parity check codes are chosen as the channel encoding method to encode the Wyner-Ziv frames in distributed video coding. These codes involve much complicated encoding and decoding algorithms, and might increase the processing time of the system. In this paper, we use the codes with simpler encoding and decoding algorithms, the Reed Solomon codes, and compare the performance...
The HEVC (H.265) standard has brought in significant improvement in terms of coding efficiency. However, this reduction in bit rate (almost half) comes along with an increase in complexity resulting in a very high compression time. This paper proposes a novel method to reduce the complexity in the intra-mode encoding process. We have defined a new term called the Average Pixel Cost (APC) for a CU...
Wireless video transmission is one of the main applications of wireless local area networks. And high-speed video transmission can be achieved with the application of MIMO-OFDM technologies. But the conventional digital video transmission in MIMO has to degrade performances of all the antennas to be the same as the antenna with the worst channel gain. Based on H.264/AVC and ParCast, a hybrid digital-analog...
High Efficiency Video Coding (HEVC), one of the latest video compression schemes proposed by Joint Collaborative Team on Video Coding (JCT-VC) which is a partnership between International Telecommunication Union Video Coding Experts Group (ITU T-VCEG) and International Organization for Standardization Moving Picture Experts Group (ISO/IEC MPEG), has been promoted to Final Draft International Standard...
The latest video coding standard H.264/AVC achieves better video compression rates since it adopts many new features. The improvement in compression efficiency of H.264 has brought about the dramatic increase in computational complexity. In this paper an algorithm for DC mode prediction employing a new mathematical expression has been developed and analyzed computational complexity against existing...
In this paper, we propose a novel frame-level rate control algorithm for videos with complex scene in High Efficiency Video Coding(HEVC). To achieve a constant bitrate output and reduce the mismatch ratio of bitrate for time varying wireless links, the relationship of content complexity, QP and bitrate is utilized to adjust bit allocation for each GOP and frame via linear extrapolation. In addition,...
This paper addresses the patch size issue in sparse representation over learned dictionaries. A strategy for selecting the best patch size is proposed. It is empirically shown that the representation quality of natural image patches depends on the patch size considered. The proposed strategy selectively chooses the most appropriate patch size based on the resulting sparse representation error. The...
The proposed work develops an efficient multi spectral band imagery compression technique using adaptive haar wavelet transform, called tetrolet transform. Geometrical features are most important prominent factor in multispectral image processing. But existing compression algorithms are fail to preserve geometrical features at high compression ratio, which implicates the visual cognitive effects around...
In this paper a novel image compression technique based on EZW (Embedded Zero Tree Wavelet Coding) algorithm is presented. EZW algorithm encodes the image to compress it into a bit stream of high accuracy. The proposed technique uses 6 symbols instead of 4 symbols used in Shapiro's EZW algorithm. This approach can produce higher PSNR and compression ratio than EZW algorithm, without affecting the...
Image quality measures try to quantify a visual quality or analogically, an amount of distortion in a given picture. This thesis work proposes a moment based image quality assessment metric that automatically assesses the quality of an image in the discrete orthogonal moments domain. In this work, the discrete orthogonal moment namely, a Tchebichef moment is chosen and quality measure is developed...
This paper presents a novel data hiding using Integer Wavelet Transform (TWT) through lifting scheme that aims to achieve high quality of stego image. This method transforms a spatial domain cover image into a frequency domain cover image. It hides the secret message into detail coefficients (CH, CV, CD) of IWT by construct a binary image in any of selected bit in CH, CV, CD separately and compresses...
In this paper we evaluate four mainstream video encoders: H.264/MPEG-4 Advanced Video Coding, Google's VP8, High Efficiency Video Coding, and Google's VP9, studying conventional figures-of-merit such as performance in terms of encoded frames per second, and encoding efficiency in both PSNR and bit-rate of the encoded video sequences. Additionally, two platforms equipped with a large number of cores,...
Wireless video sensor networks (WVSN) are foreseen to be a key driver of the development of pervasive applications of every-day life. They trigger very challenging problems due to their constrained nature in terms of energy, bandwidth, processing and storage means. In order to be able to assess the performances of their proposals, WVSN's researchers community needs a transmission and evaluation tool...
The channel conditions vary over time in wireless communications. In order to transmit information efficiently, digital wireless communication systems choose the modulation scheme and coding adaptively. This framework is called the adaptive modulation and coding (AMC). The key problem of the framework is how to design the switching strategy. In this paper, we discuss the practical strategy for AMC...
In this paper, an efficient fast algorithm called Boundary-aided Extreme Value Detection (BEVD) is applied to predict the best direction mode, excluding the DC mode, for H.264/AVC fast intra-mode decision. The BEVD-based two-step edge detection can predict luma-4×4, luma-16x16, and chroma-8×8 modes effectively. Simulation results show that the proposed BEVD method reduces encoding time by 63 %, and...
This paper proposes a new visually lossless image compression technique for display devices. The algorithm explores the differences in error perceptibility of human visual system (HVS) for different image areas. Coding units are classified into smooth, detail and sharp areas based on local complexity and prediction errors. In order to achieve the objectives of imperceptible quality loss and high compression...
In 2011, Chen used Run Length Coding to record the repetition times of continuous data with the same value. These recorded data were then embedded in cover images by Module-based Substitution. In order to increase the quantity of repetition times of the data with the same value, in this paper, the pixel values are changed into difference values by using Median Edge Predictor (MED). The range of all...
Intra-frame coding costs much more bits than inter-frame coding in a video encoder. The Assignment of the intra-frames is independent of video contents in current CODEC. This work proposes an adaptive Delaunay triangular mesh (DTM) based motion estimation/motion compensation (ME/MC) and DCT hybrid coding scheme with an ability to perceive the change of the content of any videos and assign the intra-frame...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.