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.
The traditional multi-dimensional vector matrix discrete cosine transform compression adopts video frame segmentation of fixed block size. In fact, the texture complexities of image in different regions are usually very different, so transformation adaptively with proper block size, not only further improves the compression performance, but also gets better improvement in subject evaluation. A three-dimensional...
Variable size matrix segmentation and variable size transform are used in the colour image compression methods based on three dimensional matrix widely discrete cosine transform (3DMWDCT). However the coefficients have different statistical properties since different areas of an image and difference size blocks have difference energy centralization. 3D balance quantization based human visual system...
This paper proposes an efficient zero-block inter mode decision algorithm for high bit-rate coding in H.264/AVC, to improve computation efficiency of the previous algorithm [1]. In the proposed algorithm we suggest using zero-blocks of both 8×8 and 4×4 DCT coefficients to describe video sequences in detail, including global and local stationary characteristics. The experimental results reveal that...
Video coding technology plays a key role in various multimedia applications. H.264 is the newest video coding standard and has achieved a significant improvement in coding efficiency. The 4*4 integer transform, as one of the key techniques in H.264 video compression standard, is very important for the whole performance of H.264 codec. In this paper we propose a novel algorithm for fast and error-free...
The core of many video coding standards is formed by the Discrete Cosine Transform (DCT) for de-correlating spatial video data. When applied to symmetrical spatial data or patterns as found in graphical data, the DCT results in zerovalued sub-bands at predefined positions in the transform domain. The DCT de-correlation is further improved when scan paths are defined that omit the aforementioned zero-valued...
Quantization in H.264 is achieved in the DCT domain using scalar quantizers, which assume a sum distortion constraint and often produce considerably larger distortions on block boundaries than inside a block in the pixel domain. This biased distortion distribution degrades the rate distortion (RD) performance of H.264 intra coding whose prediction is exclusively based on boundary pixels. This paper...
In this paper, we propose a skip decision method based on the linearity of motion in Wyner-Ziv coding structure. By comparing motion vectors of theside information with respect to each key frame, decoder evaluates quality of side information. When motion in side information is estimated as linear, a good quality of side information is expected, therefore we send the skip indication to encoder and...
The H.264 standard provides significantly high compression efficiency with multiple block size Motion Estimation adopted. However, the encoding time of Motion Estimation and Discrete Cosine Transform is dramatically increased as a result. An early mode decision algorithm is proposed in this paper to control the computation complexity. It derives a threshold to make mode decisions in advance. Experimental...
This paper studies the feasibility and investigates various choices in the application of compressive sensing (CS) to object-based surveillance video coding. The residual object error of a video frame is a sparse signal and CS, which aims to represent information of a sparse signal by random measurements, is considered for coding of object error. This work proposes several techniques using two approaches-...
Video data compression uses interframe coding to remove temporal redundancy and motion compensation plays a vital role in it. Generally, the block matching techniques are used for motion compensation and the matching criterions used are mean absolute difference (MAD) and mean square error (MSE). MSE has more computation than MAD and therefore, MAD is the most preferred block matching criterion for...
We present a new method for compact representation of large image datasets. Our method is based on treating small patches from an image as matrices as opposed to the conventional vectorial representation, and encoding those patches as sparse projections onto a set of exemplar orthonormal bases, which are learned a priori from a training set. The end result is a low-error, highly compact image/patch...
H.264 is the currently state-of-the-art video compression standard performing significant improvement in coding efficiency and quality compared to other existing standard, such as MPEG-4 and H.263. The standard adapts a lot of novel techniques, like intra prediction, inter prediction and integer DCT(integer discrete cosine transform), to exploits high operational complexity for reducing spatial and...
Distributed video coding (DVC) technology is investigated and payed more and more attentions in wireless video applications because of characteristics of its encoder with low-complexity and decoder with high-complexity. Its coding types can be sorted the key and Wyner-Ziv frames, key frames are with conventional intra-coding mode, Wyner-Ziv frames are coded by an encoder that is composed of quantizer...
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.