1,508 research outputs found
An overview Survey on Various Video compressions and its importance
With the rise of digital computing and visual data processing, the need for storage and transmission of video data became prevalent. Storage and transmission of uncompressed raw visual data is not a good practice, because it requires a large storage space and great bandwidth. Video compression algorithms can compress this raw visual data or video into smaller files with a little sacrifice on the quality. This paper an overview and comparison of standard efforts on video compression algorithm of: MPEG-1, MPEG-2, MPEG-4, MPEG-
Blockwise Transform Image Coding Enhancement and Edge Detection
The goal of this thesis is high quality image coding, enhancement and edge detection. A unified approach using novel fast transforms is developed to achieve all three objectives. Requirements are low bit rate, low complexity of implementation and parallel processing. The last requirement is achieved by processing the image in small blocks such that all blocks can be processed simultaneously. This is similar to biological vision. A major issue is to minimize the resulting block effects. This is done by using proper transforms and possibly an overlap-save technique. The bit rate in image coding is minimized by developing new results in optimal adaptive multistage transform coding. Newly developed fast trigonometric transforms are also utilized and compared for transform coding, image enhancement and edge detection. Both image enhancement and edge detection involve generalised bandpass filtering wit fast transforms. The algorithms have been developed with special attention to the properties of biological vision systems
Noise Reduction for CFA Image Sensors Exploiting HVS Behaviour
This paper presents a spatial noise reduction technique designed to work on CFA (Color Filtering Array) data acquired by CCD/CMOS image sensors. The overall processing preserves image details using some heuristics related to the HVS (Human Visual System); estimates of local texture degree and noise levels are computed to regulate the filter smoothing capability. Experimental results confirm the effectiveness of the proposed technique. The method is also suitable for implementation in low power mobile devices with imaging capabilities such as camera phones and PDAs
Exploring Long- and Short-Range Temporal Information for Learned Video Compression
Learned video compression methods have gained a variety of interest in the
video coding community since they have matched or even exceeded the
rate-distortion (RD) performance of traditional video codecs. However, many
current learning-based methods are dedicated to utilizing short-range temporal
information, thus limiting their performance. In this paper, we focus on
exploiting the unique characteristics of video content and further exploring
temporal information to enhance compression performance. Specifically, for
long-range temporal information exploitation, we propose temporal prior that
can update continuously within the group of pictures (GOP) during inference. In
that case temporal prior contains valuable temporal information of all decoded
images within the current GOP. As for short-range temporal information, we
propose a progressive guided motion compensation to achieve robust and
effective compensation. In detail, we design a hierarchical structure to
achieve multi-scale compensation. More importantly, we use optical flow
guidance to generate pixel offsets between feature maps at each scale, and the
compensation results at each scale will be used to guide the following scale's
compensation. Sufficient experimental results demonstrate that our method can
obtain better RD performance than state-of-the-art video compression
approaches. The code is publicly available on:
https://github.com/Huairui/LSTVC.Comment: arXiv admin note: text overlap with arXiv:2207.0458
Combined Source and Channel Strategies for Optimized Video Communications
ISBN 978-953-7619-70-
Implementation of Vector Quantization for Image Compression - A Survey
This paper presents a survey on vector quantization for image compression. Moreover it provides a means of decomposition of the signal in an approach which takes the improvement of inter and intra band correlation as more lithe partition for higher dimension vector spaces. Thus, the image is compressed without information loss using artificial neural networks (ANN). Since 1988, a growing body of research has examined the use of VQ for the image compression. This paper discusses about vector quantization, its principle and examples, its various techniques and image compression its advantages and applications. Additionally this paper also provides a comparative table in the view of simplicity, storage space, robustness and transfer time of various vector quantization methods. In addition the proposed paper also presents a survey on different methods of vector quantization for image compression
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