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The availability of inexpensive cameras enables alternative applications beyond personal video communication. For example, surveillance of rooms and home premises is such an alternative application, which can be extended with remote viewing on hand-held battery-powered consumer devices. Scalable wavelet image/video coding is attractive for this application since the video can be scaled easily to many...
The video quality of the conventional single description (streaming) coding (SDC) is vulnerable to transmission errors. Once a video frame is lost, it is likely to cause error propagation to the subsequent received frames, and this increases the difficulty of whole-frame error concealment by its preceding and/or succeeding reference frames. The temporal Multiple Description Coding (T-MDC) is more...
In the consumer electronics market, the need for error tolerance in wireless systems is increasing especially from I-Q imbalances and non-linearity in RF front-end. In most applications such as encoded image transmission, not all bits are equally important. However, current error tolerance schemes give equal importance to all transmitted bits. In this paper, an OFDM data transfer methodology that...
Signature verification is one of the central issues in our everyday life, especially in financial administration. Signature verification (SV) systems have been founded on human biometric features which are different from person to person. A desperate trouble with signatures is the mismatch between original signatures generated by an individual. In this paper, the existing methods dealing with these...
Many papers have shown that burst loss causes more severe damage to the reconstructed video quality than random loss for the same packet loss rate. With traditional interleaving methods, the consecutive lost packet positions will be interleaved to random positions, and after interleaving, the PSNR of burst loss can be close to the PSNR of random loss for the same packet loss rate. In this paper, a...
New method improving B-slice prediction is proposed. By combining the optical flow concept and high accuracy gradients evaluation we construct the algorithm which allows pixel-wise refinement of motion. This approach does not require any signaling for decoder. According to tests with WQVGA sequences bit-saving of 2%-6% can be achieved using this tool.
The hybrid coding method combining the predictive coding with the orthogonal transformation and the quantization is mainly used recently. This paper proposes a new hybrid parallel Intra Coding based on interpolative prediction which uses correlations between neighboring pixels, including non-causal pixels. In order to get high prediction performance, the optimal quantizing scheme, which is used to...
Currently, depth sequences generated by automatic depth estimation suffer from the temporal inconsistency problem. Estimated depth values of some objects vary in adjacent frames, whereas the objects actually remain on the same depth planes. These temporal depth errors significantly impair the visual quality of the synthesized virtual view as well as the coding efficiency of the depth sequences. Since...
Most practical steganographic algorithms for empirical covers embed messages by minimizing a sum of per-pixel distortions. Current near-optimal codes for this minimization problem are limited to a binary embedding operation. In this paper, we extend this work to embedding operations of larger cardinality. The need for embedding changes of larger amplitude and the merit of this construction are confirmed...
To acquire images of dynamic scenes from multiple points of view simultaneously, the acquisition time of vision sensors should be synchronized. Although the influences of background light and the amplitude fluctuation have been successfully eliminated, it is still necessary to distinguish the frame indexes of multiple synchronized vision sensors. In this paper, an illumination-based synchronization...
View synthesis using depth maps is a well-known technique for exploiting the redundancy between multi-view videos. In this paper, we deal with the bitrates of view synthesis at the decoder side of FTV that would use compressed depth maps and views. Both inherent depth estimation error and coding distortion would degrade synthesis quality. The focus is to reduce bitrates required for generating the...
In this paper, we propose an intra-prediction system that is both parallel friendly and with high coding efficiency. This is achieved by combining a novel prediction strategy that reduces serial dependencies and a novel, multi-directional and adaptive prediction system. The resulting technique is compared with state-of-the-art ITU-T H.264/MPEG-4 AVC. We observe a 2× and 8× increase in parallelism...
During view synthesis based on depth maps, also known as Depth-Image-Based Rendering (DIBR), annoying artifacts are often generated around foreground objects, yielding the visual effects that slim silhouettes of foreground objects are scattered into the background. The artifacts are referred as the boundary noises. We investigate the cause of boundary noises, and find out that they result from the...
Compression of depth maps is important for “image plus depth” representation of multiview images, which enables synthesis of novel intermediate views via depth-image-based rendering (DIBR) at decoder. Previous depth map coding schemes exploit unique depth characteristics to compactly and faithfully reproduce the original signal. In contrast, given that depth maps are not directly viewed but are only...
H.264/AVC employs intra prediction to reduce spatial redundancy between neighboring blocks. Different directional prediction modes are used to cater diversified video content. Although it achieves quite high coding efficiency, it is desirable to analyze its drawbacks in the existing video coding standard, since it allows us to design better ones. Basically, even after intra prediction, the residue...
Multi-view video coding exploits inter-view redundancies to compress the video streams and their associated depth information. These techniques utilize disparity estimation techniques to obtain disparity vectors (DVs) across different views. However, these methods contribute to the majority of the computational power needed for multi-view video encoding. This paper proposes a solution for fast disparity...
Fast algorithm for path planning is helpful for artificial intelligence. Genetic Algorithm (GA) is a typical evolution method, used widely in path planning. A new GA based on path network is proposed in this paper. Efficient chromosome encoding strategy provided guarantees, and each chromosome represents a feasible path, avoiding the searching circulation. Variation happens at certain positions, making...
Compressed sensing (CS) is a technique for acquiring and reconstructing a signal utilizing the prior knowledge that it is sparse or compressible. In this paper, we present a Wyner-Ziv image coding framework, which combines the traditional image coding and compressed sensing. In our method, the image separate into two parts according to pixel location: the down-sampling image is encoded by traditional...
In this paper we introduce a novel concept for Intra coding of pictures especially suitable for representing smooth image segments. Traditional block based transform coding methods cause visually annoying blocking artifacts for image segments with gradually changing smooth content. The proposed solution overcomes this drawback by defining a fully continuous surface of sample values approximating the...
A modified orthogonal search (OS) algorithm via gradient descent is proposed for fast motion estimation (ME). Gradient descent method, a first-order optimization algorithm in machine learning, is employed in video coding to reduce the ME time for coding performance enhancement. An improved OS algorithm is created in our proposed method. Through this method, the number of search points is reduced significantly...
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