Enhanced Predictive Zonal Search Research Articles

An FPGA design and implementation of EPZS motion estimation algorithm for 3D H.264/MVC standard

In the Three-Dimensional H.264 Multi-view Video Coding (3D H.264/MVC), the original 3D Video (3DV) sequence is a combination of variable video frames captured for the same object by different cameras. Therefore, in order to transmit 3DV content over limited-resources networks, a highly-efficient compression mechanism must be applied, while achieving a better reception quality. Moreover, in real-time applications such as 3DV conference and streaming, it is mandatory that the process of 3DV compression/decompression is speedy. Because it is known that most of the design complexity of the utilized 3D H.264/MVC codec come from the encoder part not from the decoder part, where the Motion Estimation (ME) process presents the highest computational complexity. In this work, an efficient implementation of the Enhanced Predictive Zonal Search (EPZS) ME algorithm is introduced for the 3D H.264/MVC standard. The EPZS algorithm is one of the most common and best ME algorithms. The overall inter-frame and inter-view prediction mechanisms including Motion Compensation (MC) and ME have been implemented. For validation and comparative analysis purposes, the outcomes of the suggested 3DV design for the EPZS ME algorithm are contrasted to more state-of-the-art ME algorithms. The suggested architecture of the EPZS ME algorithm is implemented in VHDL, synthesized utilizing Xilinx Virtex-6 FPGA and Xilinx ISE Design Suite 13.3, simulated employing ModelSim SE 6.5, and validated utilizing MATLAB SIMULINK. Experimental results prove that the suggested architecture achieves a low hardware complexity implementation and high-speed of 3D H.264/MVC compression process. This can be exploited for the utilization of the proposed work for real-time 3DV applications.

Optimized Predictive Zonal Search (OPZS) for block-based motion estimation

Predictive Motion Estimation (ME) techniques are fast ME algorithms that have been widely used in video CODECs due to their performance efficiency and low computational complexity. In this paper, a new approach named Optimized Predictive Zonal Search (OPZS) is proposed, which improves the state-of-the-art Enhanced Predictive Zonal Search (EPZS) algorithm. The new initial predicted motion vectors employ fewer, but more optimized predictors, as well as improve the termination procedure. The proposed OPZS not only achieves better output quality and significantly higher compression ratio, but also reduces the number of search points and ME processing time even further. Simulation results after encoding 6 different video test sequences with OPZS along with EPZS and three other algorithms implemented under the same conditions has shown up to 33% compression ratio enhancement. This is achieved by searching up to 14% less points, which means less computational complexity and up to 0.4dB higher PSNR values. The simplicity and high performance of OPZS make it more practical for implementation on both hardware and software platforms. Since OPZS provides a combination of low computational complexity and high quality encoded images, it is energy efficient and suitable for portable video processing in computation- or power-constrained applications. Furthermore, because of the higher compression ratio this newly proposed algorithm is more compatible with limited capacity storage media and transmission networks with limited band-width.

Hardware-friendly HEVC motion estimation: new algorithms and efficient VLSI designs targeting high definition videos

In this article the spread and iterative search (S&IS) and the low density and iterative search (LD&IS) motion estimation algorithms are presented. The proposed algorithms are hardware-friendly because they have a regular number of cycles to encode a block, they have a regular memory access and the parallelism can be better explored when compared to other published solutions. The proposed algorithms were evaluated under the high efficiency video coding reference software and compared with the state-of-art enhanced predictive zonal search (EPZS) algorithm and with the well know diamond search (DS) algorithm. The designed algorithms presented better BD-rate results than DS but they presented some losses when compared to EPZS. Since EPZS is not focused in a hardware design, it presents a lot of data dependencies, a irregular memory access, a non-deterministic number of operations to encode a block and it must store motion vectors of previously encoded frames. All these features are undesirable for many applications, including those ones focused on battery powered devices. To show the efficiency of the proposed algorithms, two architectures were designed targeting these algorithms and they were synthesized for Altera Stratix 4 and for ASIC using TSMC 90 nm standard-cells technology. Synthesis results show that the architectures are capable to process HD 1080p videos, at real time, by obtaining good results in terms of hardware resources use, power consumption and processing rate when compared to related works. The ASIC implementations are able to guarantee real-time performance for high definition videos consuming 12.5 and 13.5 mW, respectively. These results are possible because S&IS and LD&IS were developed focusing on hardware design.