In this paper, we propose a frame level rate control scheme for screencontent video (SCV) coding. Firstly, inter frame correlation (IFC) is computed to describe the similarity of successive frames for SCV. Based on t...
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ISBN:
(纸本)9781538648810
In this paper, we propose a frame level rate control scheme for screencontent video (SCV) coding. Firstly, inter frame correlation (IFC) is computed to describe the similarity of successive frames for SCV. Based on the IFC, the frames in SCV are further classified into key frames (KFs) and non-key frames (NKFs). Secondly, an efficient bit rate allocation scheme is proposed for KFs and NKFs based on the IFC and Hypothetical Reference Decoder (HRD), which can well ensure the R-D performance. Finally, rate quantization (R-Q) models for KFs and NKFs are established by considering the characteristics of the two types of frames, respectively. As such, accurate coding bits allocation at frame level can be achieved by the proposed rate control algorithm. The proposed rate control scheme introduces low coding complexity burden as well as low coding delay, enabling its application in real screen sharing scenarios. Compared with the recommended rate control scheme in HEVC, experimental results demonstrate that the proposed rate control scheme can achieve better performance in terms of both rate control accuracy and R-D performance. In particular, the average bit rate mismatch is within 1.4%, and the average R-D performance improvements are over 19%.
Block matching used in traditional hybrid coding,like intra block copy (IBC), is not always efficient to code similar or identical pattern within a picture, since they use 2-D pattern of only a few fixed sizes. To imp...
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ISBN:
(纸本)9781479970797
Block matching used in traditional hybrid coding,like intra block copy (IBC), is not always efficient to code similar or identical pattern within a picture, since they use 2-D pattern of only a few fixed sizes. To improve the coding efficiency of such repeated pattern with a flexible size, an intra string copy method is proposed in this paper. The proposed string copy is flexible in the sense that it allows string matching of variable sizes and shapes. For the matched strings, the relative distance from reference sample position to current sample position is coded as well as the matching length. To enable fast encoder search, hash function is employed to quickly identify the reference pixels in the previously coded areas by hash lookup table. Moreover, the string matching is applied not only the previously coded CUs but also the current CU. The simulation results report that the proposed method achieves 12.3% and 11% BD-rate savings for 1080P RGB and YUV respectively in full frame IBC condition.
This paper proposes a noise reduction method for screen content coding using HEVC. The proposed method focuses on that the histograms of pixel values for screencontent have distinct and sparse peaks respectively. Thi...
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This paper presents fast and efficient intra prediction algorithms for screen content coding (SCC). The proposed algorithms focus on smooth regions frequently appeared in screencontent videos, which have the characte...
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The line-based intra block copy (IntraBC) technique is newly proposed in the High Efficient Video coding (HEVC) Range Extensions to deal with repeated patterns within a picture for screen content coding. One challenge...
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ISBN:
(纸本)9781479957521
The line-based intra block copy (IntraBC) technique is newly proposed in the High Efficient Video coding (HEVC) Range Extensions to deal with repeated patterns within a picture for screen content coding. One challenge for line-based IntraBC is the large overhead by transmitting displacement vectors (DV) for each line. In this paper, a DV prediction is proposed to reduce such an overhead. Moreover, a flipping copy based prediction is proposed to better exploit the correlations within screencontent. Experimental results show that our scheme can provide a BD-rate reduction of 11.0% compare with the HEVC Range Extension anchor with the encoding time increased by 23% and no decoding time increase.
With the rapid development of electronic and multimedia technologies, screencontents are widely used in video related applications. However, hash-based block matching, one of the important coding tools designed to im...
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With the rapid development of electronic and multimedia technologies, screencontents are widely used in video related applications. However, hash-based block matching, one of the important coding tools designed to improve the coding efficiency of screencontent video, is faced with the limitation of constrained block shapes. In this paper, based on the analysis of the time and storage complexity in adding nonsquare blocks to the latest block matching scheme, an improved block matching scheme is proposed by introducing two kinds of nonsquare blocks, i.e. 8 x 4 and 4 x 8 blocks to the coding tool, which can improve the coding efficiency and trade-off the efficiency and complexity. Compared with the latest HM-16.9+SCM-8.0, the proposed scheme achieves 1.47% and 0.94% bitrate saving in low delay and random access configurations with the cost of negligible encoding time increasing for all test text sequences.
With the complexity of the 5 G network environment and the diversified requirements for video transmission, multimedia content transmission in different channel environments is a direction worth studying in order to a...
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With the complexity of the 5 G network environment and the diversified requirements for video transmission, multimedia content transmission in different channel environments is a direction worth studying in order to achieve good performance of digital media content transmission systems in an open network environment. Based on the code stream structure characteristics of screencontent in HEVC, this paper has proposed a joint source channel coding (JSCC) scheme to study the transmission of compressed video in wireless channels. Combined with the clustering algorithm from the field of artificial intelligence in the environment of wireless channel classification problem, the parameters of the wireless channel and the influencing factors can be used to reduce the noise and then use the FCM (Fuzzy C-Means) clustering algorithm to classify the channel environment. According to the channel status, optimize the current remaining resources and implement channel coding through LDPC codes. By analyzing and minimizing the end-to-end distortion model, the adaptive bit rate allocation further guarantees the quality of the reconstructed video. (C) 2020 The Authors. Published by Elsevier B.V.
With the recent advances in high computing capabilities and reliable delivery networks, it is realistic to expect emerging immersive media applications such as virtual reality (VR) and 360-deg video. ISO/IEC Motion Pi...
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With the recent advances in high computing capabilities and reliable delivery networks, it is realistic to expect emerging immersive media applications such as virtual reality (VR) and 360-deg video. ISO/IEC Motion Picture Experts Group (MPEG) has launched an MPEG-I project that focuses on not just the current but also the next-generation immersive media applications. Light field (LF) is one of the candidates under consideration by MPEG-I. A LF lenslet image contains plentiful repeating patterns since each microlens captures the same scene. On the other hand, intrablock copy (IBC) in screen content coding (SCC) increases the coding efficiency of screencontent (SC) by finding the repeating patterns. SCC can be an efficient encoder for LF image compression. However, SCC is not optimized for compressing lenslet images. Therefore, we propose an efficient lenslet image coding (LIC) model using SCC to encode lenslet images based on the lenslet image characteristics. Experimental results show that our LIC model further improves the coding efficiency of SCC on lenslet images by 3.72% on average and up to 7.77% in bitrate reduction. For fast approach, LIC is faster than SCC by 44.12%. With our proposed LIC model, the encoded bitstreams are compliant with the SCC standard with an even faster decoding time. (C) 2019 SPIE and IS&T
A screen content coding (SCC) extension to high-efficiency video coding has been developed to improve the coding efficiency for videos with computer-generated text and graphics. It employs additional coding tools such...
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A screen content coding (SCC) extension to high-efficiency video coding has been developed to improve the coding efficiency for videos with computer-generated text and graphics. It employs additional coding tools such as intrablock copy and palette modes for intraprediction. Although these modes can provide high coding efficiency for screencontent videos, they cause an increase in computational complexity. This paper proposes a fast intraprediction algorithm for SCC by content analysis and dynamic thresholding. To skip unnecessary modes for a coding unit (CU), a rough CU classification is performed as a preprocessing step. Then, two early mode decision techniques are proposed by performing a fine-granular CU classification and deriving a content-dependent rule with adaptive thresholding based on the background color. To make early termination of CU partitions, another content-dependent rule with adaptive thresholding according to rate-distortion cost is derived to skip unnecessary partitions. In addition, a scene change detection method is adopted to update all content-dependent thresholds for different scenes in a sequence. Experimental results show that the proposed algorithm achieves 35.95% computational complexity reduction on average with 1.20% Bjontegaard delta bitrate loss under all intraconfiguration, which outperforms all state-of-the-art algorithms in the literature. (C) 2018 SPIE and IS&T
Technologies for coding non-camera-captured video contents have received great interests lately due to the rapid growth of application areas such as wireless display and screen sharing, etc. In response to the market ...
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Technologies for coding non-camera-captured video contents have received great interests lately due to the rapid growth of application areas such as wireless display and screen sharing, etc. In response to the market demands, the ITU-T Video coding Expert Group and ISO/IEC Motion Picture Expert Group have jointly launched a new standardization project, i.e. the HighEfficiency Video coding (HEVC) extensions on screen content coding (HEVC SCC). Several new video coding tools, including intra block copy, palette coding, adaptive color transform, and adaptive motion resolution, have been developed and adopted into HEVC SCC draft standard. This paper reviews the main features and coding technologies in the current HEVC SCC draft standard, with discussions about the performance and complexity aspects compared with prior arts.
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