Comparing Energy Efficiency of CPU, GPU and FPGA Implementations for Vision Kernels

Developing high performance embedded vision applications requires balancing run-time performance with energy constraints. Given the mix of hardware accelerators that exist for embedded computer vision (e.g. multi-core CPUs, GPUs, and FPGAs), and their associated vendor optimized vision libraries, it becomes a challenge for developers to navigate this fragmented solution space. To aid with determining which embedded platform is most suitable for their application, we conduct a comprehensive benchmark of the run-time performance and energy efficiency of a wide range of vision kernels. We discuss rationales for why a given underlying hardware architecture innately performs well or poorly based on the characteristics of a range of vision kernel categories. Specifically, our study is performed for three commonly used HW accelerators for embedded vision applications: ARM57 CPU, Jetson TX2 GPU and ZCU102 FPGA, using their vendor optimized vision libraries: OpenCV, VisionWorks and xfOpenCV. Our results show that the GPU achieves an energy/frame reduction ratio of 1.1–3.2× compared to the others for simple kernels. While for more complicated kernels and complete vision pipelines, the FPGA outperforms the others with energy/frame reduction ratios of 1.2–22.3×. It is also observed that the FPGA performs increasingly better as a vision application’s pipeline complexity grows

Dispositivos Reconfiguráveis em Processamento de Imagem – Aplicação à detecção de faixas de rodagem

O Field-Programmable Gate Array (FPGA) tem sido cada vez mais explorado e investigado como plataforma de prototipagem e implementação de sistemas em variadíssimas áreas, incluindo as de processamento de imagem e visão computacional, uma vez que a sua arquitectura massivamente paralela proporciona numerosos benefícios no desempenho, custos e gastos energéticos quando comparado com os processadores tradicionais. O principal objectivo desta dissertação consiste em desenvolver e implementar uma aplicação de detecção de faixa de rodagem automóvel baseada em FPGA, que permita identificar diferentes tipos de linhas separadoras de faixa de rodagem, nomeadamente as linhas da faixa em que se localiza o carro, as linhas das potenciais faixas e as linhas verti cais de transição de faixa, quando o carro efectua a passagem de uma faixa de rodagem para outra. Pretende-se que a aplicação abranja todos os processos de processamento, nomeadamente de aquisição de dados vídeo, o seu processamento propriamente dito e a apresentação do resultado final num monitor. Os métodos e as funções desenvolvidas foram validadas utilizando as linguagens de programação mais populares no momento, C e C++, recorrendo também a várias biblio tecas C, sendo a mais usada a biblioteca Video do ambiente de desenvolvimento Vivado HLS, cujas funções de processamento de vídeo são compatíveis com funções existentes de OpenCV. Para a implementação do sistema foi usado um Embedded Vision Bundle da Digilent, ou seja, uma placa Zybo Z7-20 em conjunto com um módulo de imagem Pcam 5CThe Field-Programmable Gate Array (FPGA) has been increasingly explored and investi gated as a platform for prototyping and system implementation in a wide range of areas, including areas of image processing and computer vision, since its massively parallel architecture provides numerous benefits in performance, cost and power consumption compared to traditional processors. The main objective of this dissertation is to develop and implement an FPGA based lane detection application, that can identify different types of lane lines, namely, the lane lines in which the car is located, the lines of the potential lanes and the vertical lines, when the car moves from one lane to another. The intention is to create an application that covers all involved processes, namely video data acquisition process, the processing of the data, and the presentation of the final result on a monitor. The developed methods and functions were validated using C and C++ programming languages, which are still the most popular worldwide. Also, several C libraries were used, Video library of Vivado HLS development environment being the most used, whose video processing functions are compatible with existing OpenCV functions. For the im plementation of the system was used a Digilent Embedded Vision Bundle, which consists of a Zybo Z7-20 board and a Pcam 5C image module

Enabling Shared Memory Communication in Networks of MPSoCs

Ongoing transistor scaling and the growing complexity of embedded system designs has led to the rise of MPSoCs (Multi‐Processor System‐on‐Chip), combining multiple hard‐core CPUs and accelerators (FPGA, GPU) on the same physical die. These devices are of great interest to the supercomputing community, who are increasingly reliant on heterogeneity to achieve power and performance goals in these closing stages of the race to exascale. In this paper, we present a network interface architecture and networking infrastructure, designed to sit inside the FPGA fabric of a cutting‐edge MPSoC device, enabling networks of these devices to communicate within both a distributed and shared memory context, with reduced need for costly software networking system calls. We will present our implementation and prototype system and discuss the main design decisions relevant to the use of the Xilinx Zynq Ultrascale+, a state‐of‐the‐art MPSoC, and the challenges to be overcome given the device's limitations and constraints. We demonstrate the working prototype system connecting two MPSoCs, with communication between processor and remote memory region and accelerator. We then discuss the limitations of the current implementation and highlight areas of improvement to make this solution production‐ready

Applying Artificial Intelligence Planning to Optimise Heterogeneous Signal Processing for Surface and Dimensional Measurement Systems

The need for in-process measurement has surpassed the processing capability of traditional computer hardware. As Industry 4.0 changes the way modern manufacturing occurs, researchers and industry are turning to hardware acceleration to increase the performance of their signal processing to allow real-time process and quality control. This thesis reviewed Industry 4.0 and the challenges that have arisen from transitioning towards a connected smart factory. It has investigated the different hardware acceleration techniques available and the bespoke nature of software that industry and researchers are being forced towards in the pursuit of greater performance. In addition, the application of hardware acceleration within surface and dimensional instrument signal processing was researched and to what extent it is benefitting researchers. The collection of algorithms that the field are using were examined finding significant commonality across multiple instrument types, with work being repeated many times over by different people. The first use of PDDL to optimise heterogenous signal processing within surface and dimensional measurements is proposed. Optical Signal Processing Workspace (OSPW) is presented as a self-optimising software package using GPGPU acceleration using Compute Unified Device Architecture (CUDA)for Nvidia GPUs. OSPW was designed from scratch to be easy to use with very little-to-no programming experience needed, unlike other popular systems such LabVIEW and MATLAB. It provides an intuitive and easy to navigate User Interface (UI) that allows a user to select the signal processing algorithms required, display system outputs, control actuation devices, and modify capture device properties. OSPW automatically profiles the execution time of the signal processing algorithms selected by the user and creates and executes a fully optimised version using an AI planning language, Planning Description Domain Language (PDDL), by selecting the optimum architecture for each signal processing function. OSPW was then evaluated against two case studies, Dispersed Reference Interferometry (DRI) and Line-Scanning Dispersed Interferometry (LSDI). These case studies demonstrated that OSPW can achieve at least21x greater performance than an identical MATLAB implementation with a further 13% improvement found using the PDDL’s heterogenous solution. This novel approach to providing a configurable signal processing library that is self-optimising using AI planning will provide considerable performance gains to researchers and industrial engineers. With some additional development work it will save both academia and industry time and money which can be reinvested to further advance surface and dimensional instrumentation research

Políticas de Copyright de Publicações Científicas em Repositórios Institucionais: O Caso do INESC TEC

A progressiva transformação das práticas científicas, impulsionada pelo desenvolvimento das novas Tecnologias de Informação e Comunicação (TIC), têm possibilitado aumentar o acesso à informação, caminhando gradualmente para uma abertura do ciclo de pesquisa. Isto permitirá resolver a longo prazo uma adversidade que se tem colocado aos investigadores, que passa pela existência de barreiras que limitam as condições de acesso, sejam estas geográficas ou financeiras. Apesar da produção científica ser dominada, maioritariamente, por grandes editoras comerciais, estando sujeita às regras por estas impostas, o Movimento do Acesso Aberto cuja primeira declaração pública, a Declaração de Budapeste (BOAI), é de 2002, vem propor alterações significativas que beneficiam os autores e os leitores. Este Movimento vem a ganhar importância em Portugal desde 2003, com a constituição do primeiro repositório institucional a nível nacional. Os repositórios institucionais surgiram como uma ferramenta de divulgação da produção científica de uma instituição, com o intuito de permitir abrir aos resultados da investigação, quer antes da publicação e do próprio processo de arbitragem (preprint), quer depois (postprint), e, consequentemente, aumentar a visibilidade do trabalho desenvolvido por um investigador e a respetiva instituição. O estudo apresentado, que passou por uma análise das políticas de copyright das publicações científicas mais relevantes do INESC TEC, permitiu não só perceber que as editoras adotam cada vez mais políticas que possibilitam o auto-arquivo das publicações em repositórios institucionais, como também que existe todo um trabalho de sensibilização a percorrer, não só para os investigadores, como para a instituição e toda a sociedade. A produção de um conjunto de recomendações, que passam pela implementação de uma política institucional que incentive o auto-arquivo das publicações desenvolvidas no âmbito institucional no repositório, serve como mote para uma maior valorização da produção científica do INESC TEC.The progressive transformation of scientific practices, driven by the development of new Information and Communication Technologies (ICT), which made it possible to increase access to information, gradually moving towards an opening of the research cycle. This opening makes it possible to resolve, in the long term, the adversity that has been placed on researchers, which involves the existence of barriers that limit access conditions, whether geographical or financial. Although large commercial publishers predominantly dominate scientific production and subject it to the rules imposed by them, the Open Access movement whose first public declaration, the Budapest Declaration (BOAI), was in 2002, proposes significant changes that benefit the authors and the readers. This Movement has gained importance in Portugal since 2003, with the constitution of the first institutional repository at the national level. Institutional repositories have emerged as a tool for disseminating the scientific production of an institution to open the results of the research, both before publication and the preprint process and postprint, increase the visibility of work done by an investigator and his or her institution. The present study, which underwent an analysis of the copyright policies of INESC TEC most relevant scientific publications, allowed not only to realize that publishers are increasingly adopting policies that make it possible to self-archive publications in institutional repositories, all the work of raising awareness, not only for researchers but also for the institution and the whole society. The production of a set of recommendations, which go through the implementation of an institutional policy that encourages the self-archiving of the publications developed in the institutional scope in the repository, serves as a motto for a greater appreciation of the scientific production of INESC TEC