Intra-mode Decision Algorithm Research Articles

A Fast Intra Mode Decision Algorithm in VVC Based on Feature Cross for Screen Content Videos

A Fast Intra Mode Decision Algorithm in VVC Based on Feature Cross for Screen Content Videos

Fast CU Size and Intra Mode Decision Algorithm in HEVC Standard

Fast CU Size and Intra Mode Decision Algorithm in HEVC Standard

Complexity reduction of versatile video coding standard: a deep learning approach

The new video coding standard, known as versatile video coding (VVC) is projected to be concluded by the end of 2020. This standard is conducted mainly to address 8k videos and emerging applications such as 360 deg and high dynamic range. Intraprediction is a part of the prediction step in the video coding that exploits spatial redundancy. This module has been improved, compared to the high-efficiency video coding (HEVC), by increasing the set of angular intraprediction modes (IPM) from 33 to 65 to model directional textures more accurately. Moreover, a quadtree plus binary tree (QTBT) structure replaced the QT of the HEVC. These improvements targeting at enhancing the coding efficiency resulted in significant coding complexity, especially in terms of encoding time. This paper fits into this context. It evokes the optimizations of the intramode and coding unit size decisions using statistical methods of fast decision and deep learning. A fast intramode decision algorithm is proposed for the different binary depths of the QTBT structure. Thus, an optimization by deep learning for square blocks is also included. Results show that the combinations of these two approaches can significantly reduce the complexity of the VVC encoder. Under the all intra (AI) configuration, a reduction of about 61.04% of the intraencoding time is achieved while maintaining an acceptable rate-distortion performance.

Fast Intra Mode Decision Algorithm for HEVC Based on Block Textural Properties

In order to achieve greater coding efficiency compared with the previous video coding standards, various advanced coding techniques are used in the High Efficiency Video Coding (HEVC) standard, such as a flexible partition and a large number of intra prediction modes. However, these techniques lead to much greater complexity that restricts HEVC from realtime applications. To solve this problem, a fast intra mode decision algorithm is proposed in this paper that uses the block’s textural properties to determine the partition depth range and decide whether to split or skip smaller sizes of the coding unit. Besides that, the number of candidate modes for the rough mode decision process is also reduced depending on the block’s property. Experimental results for the recommended test sequences by the JCT-VC show that the proposed algorithm can save an average of 44% encoder time with a slight loss in performance compared to the reference software HM-16.20.

Fast intra-prediction algorithms for high efficiency video coding standard

High efficiency video coding (HEVC) is the latest video compression standard that provides significant performance improvement on the compression ratio compared to all existing video coding standards. The intra-prediction procedure plays an important role in the HEVC encoder, and it is being achieved by providing up to 35 intra-modes with a larger coding unit requiring a high computational complexity that needs to be alleviated. Toward this end, the paper proposes two fast intra-mode decision algorithms that exploit the features of video sequences. First, an early detection of zero transform and quantified coefficients method is applied to generate threshold values employed for early termination of the intra-decision process and hence accelerates the encoding procedure. Another fast intra-mode decision algorithm is elaborated that relies on a refinement technique. Based on statistical analyses of frequently chosen modes, only a small part of the candidate modes is chosen for intra-prediction process, which reduces the complexity of the intra-encoding procedure. The performance of the proposed algorithms is verified through comparative analysis of encoding time, visual image quality, and compression ratio. Compared to HM 10.0, the encoding time reduction can reach 69% with only a slight degradation of image quality and compression ratio.

Fast Video Encoding Algorithm for the Internet of Things Environment Based on High Efficiency Video Coding

Video data for the Internet traffic is increasing, and video data transmission is important for consideration of real-time process in the Internet of Things (IoT). Thus, in the IoT environment, video applications will be valuable approach in networks of smart sensor devices. High Efficiency Video Coding (HEVC) has been developed by the Joint Collaborative Team on Video Coding (JCT-VC) as a new generation video coding standard. Recently, HEVC includes range extensions (RExt), scalable coding extensions, and multiview extensions. HEVC RExt provides high resolution video with a high bit-depth and an abundance of color formats. In this paper, a fast intraprediction unit decision method is proposed to reduce the computational complexity of the HEVC RExt encoder. To design intramode decision algorithm, Local Binary Pattern (LBP) of the current prediction unit is used as texture feature. Experimental results show that the encoding complexity can be reduced by up to 12.35% on average in the AI-Main profile configuration with only a small bit-rate increment and a PSNR decrement, compared with HEVC test model (HM) 12.0-RExt4.0 reference software.

Hierarchical Structure-Based Fast Mode Decision for H.265/HEVC

The mode decision strategy adopted in the High Efficiency Video Coding test model increases the complexity drastically. In this paper, we present a course of low-complexity fast mode decision algorithms. First, the depth information of the colocated block from a previous frame is used to predict the size of current block. Next, for a certain sized block, the inter-prediction residual is analyzed to determine whether to terminate the mode decision process or to skip unnecessary modes and split the block into smaller sizes. After inter-prediction, a hardware-oriented low-complexity fast intra-mode decision algorithm is proposed. A fast discrete cross difference is adopted to detect the dominant direction of the block. In addition, four simple but efficient early termination strategies are proposed to terminate the rate-distortion optimization process properly. The simulation results show that these proposed algorithms reduce the encoding time by 54.0%-68.4% without incurring any noticeable performance degradation. Hardware synthesis results demonstrate that the proposed fast intra-mode decision algorithm can be easily implemented on a hardware platform with fewer resources consumed.

Fast Intra Mode Decision Algorithm Based on Mode Correlation in SVC

Intra4×4 mode decision has correlation between enhancement layer and base layer in scalable video coding (SVC). In this paper, a new intra mode decision algorithm is proposed based on this correlation and the proximity of prediction directions of nine Intra4×4 prediction modes. This method is used in enhancement layer to decrease the mode numbers in enhancement layer. Experiments show that the proposed algorithm can save 27.52% encoding time on average with negligible PSNR change and small bit-rate loss.

Fast Intra Mode Decision Algorithm Based on Texture Direction Detection for H.264/AVC

Fast Intra Mode Decision Algorithm Based on Texture Direction Detection for H.264/AVC

H.264/AVC에서 DCT계수 분포를 이용한 고속 인트라 모드 결정 방법

he rate-distortion optimization (RDO) method in the H.264/AVC encoder is a technology that improves the coding efficiency, but increases the computational complexity. In this paper, a fast Intra mode decision algorithm using DCT (Discrete Cosine Transform) coefficients distribution is proposed to reduce the H.264 encoder complexity. The proposed method reduces the encoder complexity on average 68.40%, while the coding efficiency is slightly decreased compared with the H.264/AVC encoder.

Fast Intra Mode Decision Using DCT Coefficient Distribution in H.264/AVC

The rate-distortion optimization (RDO) method in the H.264/AVC encoder is an informative technology that improves the coding efficiency, but increases the computational complexity. In this letter, a fast Intra mode decision algorithm using DCT (Discrete Cosine Transform) coefficients distribution is proposed to reduce the H.264 encoder complexity. The proposed method reduces the encoder complexity on average 63.44%, while the coding efficiency is slightly decreased compared with the H.264/AVC encoder.

Fast Intra Prediction Mode Decision for H.264/AVC

SUMMARY In this letter, we present a simple but efficient intra prediction mode decision for H.264/AVC. Based on our investigation, the DC mode appears to be the superior prediction mode among the various candidates. We propose an intra-mode decision algorithm where the DC mode is chosen as a candidate for the best prediction mode. By experimental results, on average, the proposed algorithm significantly saves 81.905% of the entire encoding time compared to the H.264 reference software; besides, it reduces negligible peak signal-to-noise ratio (PSNR) values and slightly increases bitrates.

H.264/AVC 표준에서 역트리 구조를 이용하여 고속으로 화면내 모드를 결정하는 방법

The H.264/AVC standard achieves higher coding efficiency than previous video coding standards with the rate-distortion optimization (RDO) technique which selects the best coding mode and reference frame for each macroblock. As a result, the complexity of the encoder have been significantly increased. In this paper, a fast intra-mode decision algorithm is proposed to reduce the computational load of intra-mode search, which is based on the inverse tree-structure edge prediction algorithm. First, we obtained the dominant edge for each block from local edge information, then the RDO process is only performed by the mode which corresponds to dominant edge direction. Then, for the (or ) block stage, the dominant edge is calculated from its four (or ) blocks` dominant edges without additional calculation and the RDO process is also performed by the mode which is related to dominant edge direction. Experimental results show that proposed scheme can significantly improve the speed of the intra prediction with a negligible loss in the peak signal to noise ratio (PSNR) and a little increase of bits.

Fast Intra-Mode Prediction Algorithm in H.264/AVC Video Coding

A fast intra-mode decision algorithm is proposed on the basis of an inter-mode block type for inter-frames (P-slices). Each macroblock (MB) type has its own intra prediction modes (I16MB and 8× 8 chroma: 4 modes, I4MB and I8MB: 9 modes). This procedure creates a large computational complexity in addition to the inter mode decision procedure. In most cases, there is a high correlation between the best inter-mode block type and the direction of the texture edge or object boundary. Therefore, only a small number of intra-prediction modes are chosen to determine the best intra mode based on this correlation. We experimentally verify that the proposed scheme can significantly improve the speed of the overall encoding time with a negligible loss of image quality and a minimal bit increase. The average loss in PSNR was -0.012 ~ 0.036 dB and the bit increment was approximately -0.194 ~ 0.751%.