In this paper, we present an interactive virtual display system to facilitate the ubiquitous user interaction with heterogeneous devices. By using small-size programmable hardware and wearable sensors, any display device (referred to as display surface) can act as a thin client for users to interact with the different remote devices. Under a flexible system architecture for local and remote devices' communication and collaboration, several techniques, such as adaptive screen compression, interactive ROI control, and accelerometer-based pointing input, are developed to improve the system performance and user experience. Evaluations show that the proposed system can efficiently utilize the remote computing resources and local display capabilities of ubiquitous devices, which will greatly benefit interactive multimedia applications.

In this paper, we propose a novel approach for high-dynamic-range (HDR) texture compression (TC) suitable for rendering systems of different capacities. Based on the previously proposed DHTC scheme, we first work out an improved joint-channel compression framework, which is robust and flexible enough to provide compressed HDR textures at different bit rates. Then, two compressed HDR texture formats based on the proposed framework are developed. The 8 bpp format is of near lossless visual quality, improving upon known state-of-the-art algorithms. And, to our knowledge, the 4 bpp format is the first workable 4 bpp solution with good quality. We also show that HDR textures in the proposed 4 bpp and 8 bpp formats can compose a layered architecture in the texture consumption pipeline, to significantly save the memory bandwidth and storage in real-time rendering. In addition, the 8 bpp format can also be used to handle traditional low dynamic range (LDR) RGBA textures. Our scheme exhibits a practical solution for compressing HDR textures at different rates and LDR textures with alpha maps.

In this paper, we propose a novel compression scheme for medical images with extended bit depth. Our scheme efficiently utilizes the VOI (value of interest) settings of the medical images, so that only a small part of the coded bit-stream is needed at the decoder to lossless display the original image with recommended VOI parameters. Gray-Golomb coding is used to support VOI progressive transmission. In addition, the pixel domain bit-plane coding enables accurate distortion estimation at pixel level for any truncated bit-stream. Compared to JPEG2000, our scheme achieves much higher VOI performance with very slight overall bit-rate increase.

In this paper, we propose a simple and effective scheme for screen image scaling, targeting at real-time applications like remote desktop and screen sharing. To balance visual quality and complexity, we build our scheme upon bilinear interpolation and devise a content adaptive post-processing method. Our scheme keeps the text/graphics regions of screen images as sharp as the original while avoiding magnifying noise and artifacts in the picture regions. Further, the involved operations are quite suitable for hardware acceleration. When implemented on commodity GPUs, our scheme achieves a frame rate more than 300 fps, which is fast enough for practical use.

It has been commonly recognized that multiple bit-rate (MBR) encoding provides a concise method for video streaming over bandwidth-fluctuant networks. The key problem of the MBR technique lies in how to seamlessly switch one bit-stream to another one. To tackle this problem, we propose a bit-stream switching framework based on the Wyner-Ziv coding. Within the propose framework, the multiple bit-streams can be individually encoded without data exchange, which also supports the random switching at any desired frame without affecting the original coding efficiency of the regular bit-stream. In particular, two different implementation schemes under the same framework are presented. Different from the traditional switching schemes, the proposed method can use the same switching frame for the switching from any other bit-stream to the current one, which means less storage and less encoding efforts. Simulation results and comparison between the proposed method and the traditional switching method in H.264 are also presented