† Abstract. This paper presents a new RD optimal motion estimation and mode decision for fast H.264/AVC bit-rate reduction. In our proposed RD model, the prediction error is estimated according to the input motion information and the picture self property. This prediction error estimation is free from computing SSD/SAD. Along with the macroblock partition process, our proposed method significantly reduces the transcoding complexity. Experimental results show that our proposed method can improve the coding efficiency about 5 dB with similar speed, compared with the motion reuse transcoder.

Modern digital family technology enables people surf the Internet and watch videos via a large screen. This paper proposes an effective scheme for using hand gestures rather than the common remote controllers to browse the web pages on a large TV screen. The proposed scheme models four gesture modes: mouse mode, scroll mode, zoom mode and input mode to help the user browse web pages naturally and comfortably. Then we combine RGB, depth, motion information and face detection to achieve accurate and real-time hand segmentation and gesture recognition for enabling the four gesture modes. The experiments show the proposed scheme works well in various illumination environments and complicated backgrounds with multiple moving humans. The recognition accuracy of hand shapes in the proposed scheme arrives at 98.50%, and the successful rate for visual digits input reaches 89.00%. Furthermore, the frame rate of the hand-gesture detection and recognition is about 18 fps. Thus the scheme is accurate, real-time and natural.

Interactive screen sharing requires extremely low latency end-to-end transmission, which in turn requires highly efficient and low-complexity screen compression. In this paper, we present a block-based low-complexity screen compression scheme, in which multiple block modes are adopted to exploit the intra- and inter-frame redundancies. In particular, we classify the intra-coded blocks to pictorial blocks and textual blocks using a proposed fast block classification algorithm, which exploits the discriminative features between the pictorial and the textual blocks. Then, we design a low-complexity, yet efficient, algorithm to compress the textual blocks. We use base colors and escape colors to represent and quantize the textual pixels, which not only achieves high compression ratios but also preserves a high quality on textual pixels. The two-dimensionally predictive index coding and hierarchical pattern coding technologies are used to exploit local spatial correlations and global pattern correlation, respectively. To further utilize the correlation between the luminance and chrominance channels, we propose a joint-channel index coding method. We compare the coding efficiency and the computational complexity of the proposed scheme against the standard image coding schemes such as JPEG, JPEG2000, and PNG, the compound image compressor HJPC, and the popular video coding standard H.264. We also compare the visual quality of the proposed scheme against H.264 intra coding, JPEG2000, and HJPC. The evaluation results show that the proposed scheme achieves superior or comparable compression efficiency with much lower complexity than other schemes in most of the cases.

Screen is becoming a new dimension in cloud computing platforms, and low latency screen sharing in unreliable networks is becoming more and more important. Due to the different characteristics between the screen codecs and video codecs, current transmission technologies on low-latency video streaming cannot be directly applied to screen sharing. So in this paper we first theoretically analyze the difference in latency performance between ARQ and FEC for the UDP-based screen sharing. Then, considering the characteristics of the main-stream screen codecs, we propose an improved ARQ scheme to decrease the transmission latency. The experimental results show that the proposed system achieves better latency performance than the popular systems.

This paper presents a block-based low-complexity screen compression scheme. In this scheme, the input screen is split into non-overlapping blocks which are classified as pictorial blocks and textual blocks. We design a low-complexity yet efficient algorithm to compress the textual blocks. We use base colors plus escape pixels to represent and quantize the text pixels, and such quantization mechanism not only achieves high compression efficiency but also keeps low encoding/decoding complexity. We also propose the two-direction predictive index coding and hierarchical pattern coding technologies to utilize the local spatial correlation and the global pattern correlation for text pixels. In addition, to utilize the correlation between the luminance and chrominance channels, we propose a joint-channel index coding method to further improve the compression efficiency. The compression efficiency and complexity of the proposed method is evaluated against the popular image codecs JPEG/JPEG200 and PNG, a recent published screen compression scheme HJPC as well as the popular video codec H.264.

In this paper, we present a browser-friendly hybrid JPEG/PNG codec for compound images. First we employ a simple yet efficient block classification algorithm to identify the blocks to pictorial and textural ones. And then JPEG is used to encode the pictorial blocks and PNG is used for textual blocks. Our evaluation results show that our codec significantly outperforms JPEG and PNG in terms of rate-distortion performance, and also it outperforms JPEG, JPEG2000 and DjVu in terms of visual quality. Moreover, since JPEG and PNG are naturally supported by modern browsers, the coded images generated from our proposed coder can be natively supported by browsers and possible to be widely deployed in Web applications.

Mobile and cloud computing have emerged as the new computing platforms and are converging into a powerful cloud-mobile computing platform. This article envisions a virtualized screen as a new dimension in such a platform to further optimize the overall computing experience for users. In a virtualized screen, screen rendering is done in the cloud, and delivered as images to the client for interactive display. This enables thin-client mobile devices to enjoy many computationally intensive and graphically rich services. Technical challenges are discussed and addressed. Two novel cloud-mobile applications, Cloud Browser and Cloud Phone, are presented to demonstrate the advantages of such a virtualized screen.

In this paper, we propose an efficient encoding solution for the screen-sharing applications with multiple clients connected. We first present a lightweight screen codec to compress the complicated screen content. Based on the architecture of the proposed codec, we propose a one-pass encoding algorithm for multiple bit-rates. The one-pass encoding algorithm enables the host to only involve in one-pass encoding process for multiple bitrates, and as a result the computation complexity of the host is decreased significantly. Specially, in the limited computing-resource case, the one-pass encoding algorithm can improve the screen-sharing performance by about 43%, in terms of framerates the clients can get. In addition, based on our codec, we propose a fast screen transcoding scheme for the data-center based screen-sharing applications.

To test the possibility of producing the novel vaccine in plants against diarrhea normally found in neonatal and newly weaned piglets, the faeG gene, encoding a major F4ac fimbrial subunit protein, was introduced into the tobacco chloroplast genome. After two rounds of selection under spectinomycin, we obtained the transgenic plants nearly homoplasmic. RNA gel blot analysis indicated that faeG and the antibiotic selective gene aminoglycoside 3' adenylyltransferase (aadA) were highly transcribed as a dicistron, while the translational level of recombinant FaeG in transplastomic tobacco was about 0.15% of total soluble protein. The immunogenicity of recombinant FaeG produced in tobacco chloroplasts was confirmed by the observation that FaeG-specific antibodies were elicited in mice immunized with total soluble protein of transgenic plants, as well as the result that mouse sera stimulated by chloroplast-derived recombinant FaeG could neutralize F4ac enterotoxigenic Escherichia coli (ETEC) in vivo. This study provides a new alternative for producing the ETEC vaccine using the chloroplast expression system.

In this paper, we present a proxy-based mobile web browser with rich experiences. We use the server-side web parsing and rendering to leverage the browser computing logic. We use a composite screen format to represent the display of the web content, incorporating the web background screen and the dynamic web objects. And then we employ a slice-based screen encoding scheme to efficiently compress the web background screen. Besides the display screen of the web content, we also send the side information of the web objects to enable the designed object-level interaction mechanisms. The experimental results show that our browser can achieve the superior browsing speed, compared with the native browser and yield much better visual quality than the existing proxy-based browser

Estimation of the homoplasmy of transgene in chloroplast is a necessary step in chloroplast transformation. This task is usually achieved by Southern blot analysis, which is laborious, time-consuming, requires large amounts of plant materials and needs hazardous radioisotopes in some cases. To develop a fast, sensitive, stable and effective technique for determining the homoplasmy of transgene in chloroplast, one real-time PCR system based on TaqMan probe technique was developed for evaluating the homoplasmy degree. In the real-time PCR system, one assay targets the exogenous faeG gene, and another one the tobacco chloroplast reference gene, maturase gene within the trnK intron (matK). The homoplasmy of the transgene was determined by the comparison of copy number of faeG and matK. The analyzed results of 17 transplastomic tobacco lines using the developed real-time PCR system were consistent with those from Southern blot analysis, indicating that the real-time PCR method is suitable for estimating the homoplasmy degree of transplastomic plant with the advantages of high efficiency and throughput, low cost and saving time.

The pervasive computing environment and the wide network bandwidth provide users more opportunities to utilize remote computing resources. In this paper, we introduce a high-performance remote computing platform to enable thin clients to access the applications in remote servers. Our system employs a compression-friendly model, where all the data redundancies are exploited in the compression viewport. Within this model, we also propose a unified coding scheme to efficiently compress the vast-spectral screens. Several mechanisms are further proposed to improve interactivity and reduce the bandwidth consumption in the system, including adaptive transmission for heterogeneous display devices. Simulations with real applications demonstrate that our system significantly outperforms previous thin-client systems. Especially for video playback under moderate- and low-bandwidth network conditions, our system can achieve the frame update rate 5 times as high as the previous counterparts.

L'invention concerne un "generateur d'affichage distant" utilisant diverses techniques pour obtenir des affichages haute-fidelite avec des experiences d'applications interactives tres reactives pour les clients sur une plage etendue de bandes passantes de reseaux pour des applications hebergees a distance. En general, le generateur d'affichage distant utilise comme noyau une architecture d'affichage distant compatible avec la compression. Avec cette architecture de compression, des donnees d'ecrans reelles provenant d'un serveur distant sont extraites de la memoire tampon d'affichage trame par trame, et ensuite compressees avec un codec d'ecran unifie. D'autres technologies notamment des modeles de mises a jour d'ecran synchronisees et des mecanismes de transmission adaptatifs, sont ensuite integres aux divers modes de realisation du generateur d'affichage distant pour ameliorer l'experience generale de l'utilisateur par l'amelioration de la qualite d'affichage et la capacite de reaction a l'interaction de l'utilisateur avec des applications hebergees a distance.