873 research outputs found
Optimized Transmission of JPEG2000 Streams Over Wireless Channels
The transmission of JPEG2000 images over wireless channels is examined using reorganization of the compressed images into error-resilient, product-coded streams. The product-code consists of Turbo-codes and Reed-Solomon codes which are optimized using an iterative process. The generation of the stream to be transmitted is performed directly using compressed JPEG2000 streams. The resulting scheme is tested for the transmission of compressed JPEG2000 images over wireless channels and is shown to outperform other algorithms which were recently proposed for the wireless transmission of images
Emergency TeleOrthoPaedics m-health system for wireless communication links
For the first time, a complete wireless and mobile emergency TeleOrthoPaedics system with field trials and expert opinion is presented. The system enables doctors in a remote area to obtain a second opinion from doctors in the hospital using secured wireless telecommunication networks. Doctors can exchange securely medical images and video as well as other important data, and thus perform remote consultations, fast and accurately using a user friendly interface, via a reliable and secure telemedicine system of low cost. The quality of the transmitted compressed (JPEG2000) images was measured using different metrics and doctors opinions. The results have shown that all metrics were within acceptable limits. The performance of the system was evaluated successfully under different wireless communication links based on real data
A reduced-reference perceptual image and video quality metric based on edge preservation
In image and video compression and transmission, it is important to rely on an objective image/video quality metric which accurately represents the subjective quality of processed images and video sequences. In some scenarios, it is also important to evaluate the quality of the received video sequence with minimal reference to the transmitted one. For instance, for quality improvement of video transmission through closed-loop optimisation, the video quality measure can be evaluated at the receiver and provided as feedback information to the system controller. The original image/video sequence-prior to compression and transmission-is not usually available at the receiver side, and it is important to rely at the receiver side on an objective video quality metric that does not need reference or needs minimal reference to the original video sequence. The observation that the human eye is very sensitive to edge and contour information of an image underpins the proposal of our reduced reference (RR) quality metric, which compares edge information between the distorted and the original image. Results highlight that the metric correlates well with subjective observations, also in comparison with commonly used full-reference metrics and with a state-of-the-art RR metric. © 2012 Martini et al
Scalable video/image transmission using rate compatible PUM turbo codes
The robust delivery of video over emerging wireless networks poses many challenges due to the heterogeneity of access networks, the variations in streaming devices, and the expected variations in network conditions caused by interference and coexistence. The proposed approach exploits the joint optimization of a wavelet-based scalable video/image coding framework and a forward error correction method based on PUM turbo codes. The scheme minimizes the reconstructed image/video distortion at the decoder subject to a constraint on the overall transmission bitrate budget. The minimization is achieved by exploiting the rate optimization technique and the statistics of the transmission channel
Minimum Distortion Variance Concatenated Block Codes for Embedded Source Transmission
Some state-of-art multimedia source encoders produce embedded source bit
streams that upon the reliable reception of only a fraction of the total bit
stream, the decoder is able reconstruct the source up to a basic quality.
Reliable reception of later source bits gradually improve the reconstruction
quality. Examples include scalable extensions of H.264/AVC and progressive
image coders such as JPEG2000. To provide an efficient protection for embedded
source bit streams, a concatenated block coding scheme using a minimum mean
distortion criterion was considered in the past. Although, the original design
was shown to achieve better mean distortion characteristics than previous
studies, the proposed coding structure was leading to dramatic quality
fluctuations. In this paper, a modification of the original design is first
presented and then the second order statistics of the distortion is taken into
account in the optimization. More specifically, an extension scheme is proposed
using a minimum distortion variance optimization criterion. This robust system
design is tested for an image transmission scenario. Numerical results show
that the proposed extension achieves significantly lower variance than the
original design, while showing similar mean distortion performance using both
convolutional codes and low density parity check codes.Comment: 6 pages, 4 figures, In Proc. of International Conference on
Computing, Networking and Communications, ICNC 2014, Hawaii, US
Design Implementation of Next Generation Wireless LAN for Mass Digital Cinema
We have been designing an over 1.2 Gbps throughput
wireless for next generation WLAN system conform with
IEEE802.11TGac’s requirements. It reaches 33 meter propagation distance by using 80MHz of bandiwdth on 5GHz band. 4x5 antennas configuration contribute 2nd-order diversity gain and maintain both the high throughput and performance. The Greenfield format preamble was proposed for its high efficiency. Novel phase rotation is employed to lower the PAPR signal. Run test for transmitting 90 frames of 40961714 pixels/frame under in-door channel model proves that the proposed system shall be considered for providing an excellent performance mass digital cinema.
Index Terms—Gigabit wireless LAN, IEEE802.11 TGac, digital
cinema transmissio
Generative Compression
Traditional image and video compression algorithms rely on hand-crafted
encoder/decoder pairs (codecs) that lack adaptability and are agnostic to the
data being compressed. Here we describe the concept of generative compression,
the compression of data using generative models, and suggest that it is a
direction worth pursuing to produce more accurate and visually pleasing
reconstructions at much deeper compression levels for both image and video
data. We also demonstrate that generative compression is orders-of-magnitude
more resilient to bit error rates (e.g. from noisy wireless channels) than
traditional variable-length coding schemes
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Design of wireless swallowable capsule with minimum power consumption and high resolution images
Medical technology has undergone major breakthroughs in recent years, especially in the area of the examination tools for diagnostic purposes. The traditional examination method for the diagnosis of gastrointestinal diseases is gastroscopy with the use of an endoscope. Wireless camera pill has created a new perspective for engineers and physicians. After years of great innovation, commercial swallowable pills have been produced and applied in clinical practice. These pills can cover the examination of the gastrointestinal system and provide to the physicians not only a lot more useful data that is not available from the traditional methods, but also elimination of the use of the painful endoscopy procedure. In this paper, a new design of the wireless swallowable pills has been proposed. It takes advantage of the benefits of every sub-system, like camera lenses, image compressor and RF sub-system. In this way our system can provide enough and accurate data to the physicians
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