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.
NoC-based architectures overcome the limitations of traditional buses by exploiting parallelism and offer large band-widths. NoC adoption also increases communication latency, which is especially penalising for data-flow applications (DF). We introduce the notifying memories (NM) concept to reduce this overhead. Our original approach eliminates useless memory requests. This paper demonstrates NM in...
This paper describes a new method of best effort decoding that substantially reduces PSNR loss especially in intra prediction and an HEVC Main-profile best-effort decoder that can decode 4:2:2 10-bit bitstreams. For inter prediction in the decoder, reference pixels are decoded in the 4:2:2 10-bit format and non-reference pixels are in the 4:2:0 8-bit format. The PSNR loss in the best-effort decoder...
The key problem in photo album compression is how to exploit the correlation among the images. In this paper, we propose a novel incremental structure from motion (SfM) based prediction method for lossless photo album compression. Unlike the previous methods, we exploit the redundancy among images through their inherent geometric relationship generated by SfM. Based on the point cloud and camera poses,...
A new image coding technique for color image based on colorization method is proposed. In colorization based image coding, the encoder selects the colorization coefficients according to the basis made from the luminance channel. Then, in the decoder, the chrominance channels are reconstructed by utilizing the luminance channel and the colorization coefficients sent from the encoder. The main issue...
Modern stereo and multi-channel perceptual audio codecs utilizing the modified discrete cosine transform (MDCT) can achieve very good overall coding quality even at low bit-rates but lack efficiency on some material with inter-channel phase difference (IPD) of about ±90 degrees. To address this issue a generalization of the lapped transform coding scheme is proposed which retains the perfect reconstruction...
Partial dynamic reconfiguration of FPGAs can be used to implement complex applications using the concept of virtual hardware. In this work we have used partial dynamic reconfiguration to implement a JPEG decoder with reduced area. The image decoding process was adapted to be implemented on the FPGA fabric using this technique. The architecture was tested in a low cost ZYNQ-7020 FPGA that supports...
the success of audio steganography techniques is to ensure imperceptibility of the embedded secret message in stego file and withstand any form of intentional or un-intentional degradation of secret message (robustness). Crucial to that using digital audio file such as MP3 file, which comes in different compression rate, however research studies have shown that performing steganography in MP3 format...
In this paper fractal encoding of images using the wavelet transform is proposed. Fractal encoding is used to produce an image with good visual quality in less encoding time. Quadtree partitioning is applied iteratively during encoding, and fractal coding is executed for JPEG, PNG and BMP HD images in two conditions: by supplying the noise to the input image and without any noise added to the input...
Traditional audio codecs based on real-valued transforms utilize separate and largely independent algorithmic schemes for parametric coding of noise-like or high-frequency spectral components as well as channel pairs. It is shown that in the frequency-domain part of coders such as Extended HE-AAC, these schemes can be unified into a single algorithmic block located at the core of the modified discrete...
In this paper, we revisit a video steganalytic scheme using the motion vector reversion-based (MVRB) feature, and make necessary improvements. Since been proposed, MVRB feature has shown its effectiveness in detecting typical motion vector-based steganographic schemes. However, as also noticed by other studies, the effectiveness of MVRB feature highly relies on the re-compression operation. If the...
Hard-real time video systems require deterministic admission control decisions to maintain high levels of predictability. These decisions can be based on the state-of-the-art schedulability analysis of tasks and flows. However, due to the pessimistic behaviour of the schedulability analysis and the uncertainties in the application, the multi-core system resources are usually under-utilised. In this...
Context: energy consumption represents an important issue with limited and embedded devices. Such devices, e.g. Smartphones, process many images, both to render the UI and for application specific purposes. Goal: we aim to evaluate the energy consumption of different image encoding/decoding algorithms. Method: we run a series of experiments on a ARM based platform, and we collected the energy consumed...
This paper investigates the magnitude of the mismatch error produced when an IDCT unit, built using the Hybrid-Logarithmic System (Hybrid-LNS), is used as part of an MPEG or videophone decoder. Mismatch errors occur when different IDCT algorithms are used in the encoding and decoding unit of an image compression system. As the IDCT forms part of the feedback loop in such a system, the errors can accumulate...
In this paper we review error resilience and concealment techniques which have been developed both within and outside the various videoconferencing standards. We consider the H.324 videoconferencing standard with its accompanying lower-level H.263 and H.223 video and multiplexing standards, MPEG-2, and MPEG-4. We then describe an error resilience algorithm commonly used with variable length codewords,...
This paper presents a new technique capable of predicting the processing time of video decoding tasks. Such technique is based on the collection and transmission in the compressed video bit-stream, of a suitable statistic information relative to the decoding process. Simulation results show that very accurate decoding time predictions can be obtained without the need of the actual decoding. These...
This paper presents an audio coding system which uses filter banks to decompose, in the frequency domain, the audio signal into constant width subbands. A specific compression is applied in each subband. This compression is achieved by means of CELP coders. In order to obtain a high audio quality, psychoacoustic models allocate dynamically the number of bits needed in each subband. A particular care...
Even with use of restart intervals, some residual errors remain in the decoded JPEG images after transmission. In order to improve the image quality, robust decoding techniques are useful. First, we propose error detection techniques, then error compensation and concealment techniques for the damaged blocks. Depending on the entropy coding and on the neighbourhood template, improvements between 3...
We describe the characteristics of a real time MPEG2 Multichannel Encoder based on a multi-DSP board. We discuss both the architectural base and the algorithm real time implementation. Due to the flexibility of the described card, realizations of other audio processing algorithms arc also possible. A brief description of these implementations is also given.
In this paper a 100 Mbit/s Huffman decoder implementation is presented. A novel approach where a parallel decoding of data mixed with a serial input has been used. The critical path has been reduced and a significant increase in throughput is achieved. The decoder is aimed at the MPEG-2 Video decoding standard and has therefore been designed to meet the required performance.
We introduce Combined Multiple Image Filter (CMIF) as a new approach for noise removal. The processed output is the Bayesian mean square error estimate of the original image. A set of four filters are selected to improve the quality of noisy image that contains regions with different characteristics. Feature vectors are computed at each pixel in order to predict the performance of the filters in estimating...
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.