scholarly journals Medical video compression using bandelet based on lifting scheme and SPIHT coding: In search of high visual quality

2019 ◽  
Vol 17 ◽  
pp. 100244
Author(s):  
Mohammed Beladgham ◽  
Yassine Habchi ◽  
Mohamed Ben aissa ◽  
Abdelmalik Taleb-Ahmed
Keyword(s):  
Video Compression ◽  
Lifting Scheme ◽  
Visual Quality ◽  
Spiht Coding

Enhancing Visual Quality of Multi-view 360 Video Compression Pipeline

2019 ◽  
pp. 135
Author(s):  
Junyoung Yun ◽  
Hong-Chang Shin ◽  
Gwangsoon Lee ◽  
Jong-Il Park
Keyword(s):  
Video Compression ◽  
Visual Quality

A Perceptually Optimized Foveation Wavelet Visible Difference Predictor Quality Metric Based on Psychovisual Properties of the Human Visual System (HVS)

2020 ◽  
pp. 268-281
Author(s):  
Abderrahim Bajit
Keyword(s):  
Visual System ◽  
Video Compression ◽  
Image Coding ◽  
Human Visual System ◽  
Quality Measurement ◽  
Region Of Interest ◽  
Visual Quality ◽  
Perceptual Quality ◽  
Foveated Imaging ◽  
Error Perception

Region of interest (ROI) image and video compression techniques have been widely used in visual communication applications in an effort to deliver good quality images and videos at limited bandwidths. Foveated imaging exploits the fact that the spatial resolution of the human visual system (HVS) is highest around the point of fixation (foveation point) and decreases dramatically with increasing eccentricity. Exploiting this fact, the authors have developed an appropriate metric for the assessment of ROI coded images, adapted to foveation image coding based on psycho-visual quality optimization tools, which objectively enable us to assess the visual quality measurement with respect to the region of interest (ROI) of the human observer. The proposed metric yields a quality factor called foveation probability score (FPS) that correlates well with visual error perception and demonstrating very good perceptual quality evaluation.

An Efficient Video Compression Encoder Based on Wavelet Lifting Scheme in LSK

2016 ◽  
Vol 13 (10) ◽  
pp. 7581-7591
Author(s):  
S. Anantha Padmanabhan ◽  
Krishna Kumar
Keyword(s):  
Wavelet Transform ◽  
Video Compression ◽  
Video Quality ◽  
Lifting Scheme ◽  
Estimation Algorithm ◽  
Discrete Wavelet ◽  
Discrete Cosine Transforms ◽  
Video Signals ◽  
Gradient Based ◽  
Wavelet Lifting

This paper presents a video compression system using wavelet lifting scheme. Video compression algorithms (“codecs”) manipulate video signals to dramatically reduce the storage and bandwidth required while maximizing the perceived video quality. There are four common methods for compression; discrete cosine transforms (DCT), vector quantization (VQ), fractal compression, and discrete wavelet transform (DWT). A gradient based motion estimation algorithm based on shapemotion prediction is used which takes advantage of the correlation between neighboring Binary Alpha Blocks (BABs), to match with the MPEG-4 shape coding case and speed up the estimation process. Then a non-redundant wavelet transform has been implemented as an iterative filter banks with down sampling operations. LSK operates without lists and is suitable for a fast, simple hardware implementation. Here the Set Partitioned Embedded bloCK coder (SPECK) image compression called Improved Listless SPECK (ILSPECK) is used. ILSPECK code a single zero to several insignificant subbands. This reduces the length of the output bit string as well as encoding/decoding time.

scholarly journals Multi-rate Sampling Wavelet Lifting Scheme Based Video Compression with Enhanced Adaptive Rood Search Integral Projections

2020 ◽  
pp. 237-245
Author(s):  
Ramesh K ◽  
Chandrika V S ◽  
Praveena P ◽  
Pazhanimuthu C ◽  
Ravindran S
Keyword(s):  
Motion Estimation ◽  
Video Compression ◽  
High Frequency ◽  
Low Frequency ◽  
Lifting Scheme ◽  
Lower Branch ◽  
Picture Quality ◽  
Inverse Filter ◽  
Search Technique ◽  
Wavelet Lifting

This paper presents the research on video compression for videos by developing a multi rate wavelet lifting scheme method which works better for both colour and grayscale videos along with Enhanced Adaptive Rood Search with Integral Projections for motion Estimation. In wavelet lifting scheme sampling is performed at different rates at the upper and lower branches. It is a powerful alternative to traditional convolution involving forward and inverse filter banks with the total amount of arithmetic computations required is substantially lesser. The ratio used is 3:2 for the upper branch and 3:1 for lower branch of lifting scheme, more low frequency coefficients are preserved as compared to high frequency coefficients to have a better picture quality with a small compromise in compression ratio. The Listless speck has been used as the Encoder and an Enhanced Adaptive Rood Search technique has been developed for motion Estimation as it improved over the problem with Adaptive Rood Search which does not consider the diagonal direction. The proposed method has produced better compression results with quality and reduced latency than the existing ones as validated in the experimentation.

Enhancing Visual Quality of Multi-view 360 Video Compression Pipeline

2019 ◽  
pp. 135
Author(s):  
Junyoung Yun ◽  
Hong-Chang Shin ◽  
Gwangsoon Lee ◽  
Jong-Il Park
Keyword(s):  
Video Compression ◽  
Visual Quality

scholarly journals AN EMBEDDED SALIENCY MAP ESTIMATOR SCHEME: APPLICATION TO VIDEO ENCODING

2007 ◽  
Vol 17 (04) ◽  
pp. 289-304 ◽  
Author(s):  
NICOLAS TSAPATSOULIS ◽  
KONSTANTINOS RAPANTZIKOS ◽  
CONSTANTINOS PATTICHIS
Keyword(s):  
Video Compression ◽  
Wavelet Decomposition ◽  
Visual Quality ◽  
Saliency Map ◽  
Video Encoding ◽  
Sigmoid Function ◽  
Topographic Feature ◽  
Feature Maps ◽  
Top Down ◽  
Bottom Up

In this paper we propose a novel saliency-based computational model for visual attention. This model processes both top-down (goal directed) and bottom-up information. Processing in the top-down channel creates the so called skin conspicuity map and emulates the visual search for human faces performed by humans. This is clearly a goal directed task but is generic enough to be context independent. Processing in the bottom-up information channel follows the principles set by Itti et al. but it deviates from them by computing the orientation, intensity and color conspicuity maps within a unified multi-resolution framework based on wavelet subband analysis. In particular, we apply a wavelet based approach for efficient computation of the topographic feature maps. Given that wavelets and multiresolution theory are naturally connected the usage of wavelet decomposition for mimicking the center surround process in humans is an obvious choice. However, our implementation goes further. We utilize the wavelet decomposition for inline computation of the features (such as orientation angles) that are used to create the topographic feature maps. The bottom-up topographic feature maps and the top-down skin conspicuity map are then combined through a sigmoid function to produce the final saliency map. A prototype of the proposed model was realized through the TMDSDMK642-0E DSP platform as an embedded system allowing real-time operation. For evaluation purposes, in terms of perceived visual quality and video compression improvement, a ROI-based video compression setup was followed. Extended experiments concerning both MPEG-1 as well as low bit-rate MPEG-4 video encoding were conducted showing significant improvement in video compression efficiency without perceived deterioration in visual quality.

scholarly journals Compressed Video Quality

2018 ◽  
Author(s):  
Iain Richardson
Keyword(s):  
Video Compression ◽  
Video Processing ◽  
Digital Video ◽  
Video Quality ◽  
Quality Measurement ◽  
Visual Quality ◽  
Compressed Video ◽  
High Definition ◽  
And Performance ◽  
Analogue To Digital

The concept of video compression goes hand in hand with the switch from analogue to digital video technology that has taken place over the last 25 years. Video delivered to televisions, computers and smartphones typically arrives in a compressed form. The bandwidth and file size savings that compression provides are a significant benefit for consumer and business applications, making it possible to send and receive high-definition video over limited capacity networks. However, for digital archive applications, compression can be problematic, especially when it introduces loss or distortion into a video signal.  ‘Born digital’ often means ‘born compressed’ and it is increasingly likely that newly-created digital video material will have gone through at least some level of lossy compression. For this reason, it is important to understand the effect of video compression on visual quality. In this paper I will introduce the concept of video compression and its relationship to video image quality. I will consider the factors that influence visual quality, including technical factors such as codecs and coding parameters, as well as the complex and only partly-understood factors that govern our perception of moving images. I will introduce methods of measuring and quantifying video quality and show how it is possible to compare the quality and performance of video processing systems, despite the limitations of quality measurement.

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