Texture Analysis with Arbitrarily Oriented Morphological Opening and Closing

13 pagesThis paper presents a fast, streaming algorithm for 1-D morphological opening on 2-D support. The algorithm is further extended to compute the complete size distribution during a single image run. The Structuring Element (SE) can be oriented under arbitrary angle that allows us to perform different orientation-involved image analysis, such as local angle extraction, directional granulometries, \etc The algorithm processes an image in constant time irrespective of the SE orientation and size, with a minimal latency and very low memory requirements. Regardless the SE orientation, it reads and writes data strictly sequentially in the horizontal scan order. Aforementioned properties allow an efficient implementation in embedded hardware platforms that opens a new opportunity of a parallel computation, and consequently, a significant speed-up

Resource Efficient Hardware Architecture for Fast Computation of Running Max/Min Filters

Running max/min filters on rectangular kernels are widely used in many digital signal and image processing applications. Filtering with a k×k kernel requires of k2−1 comparisons per sample for a direct implementation; thus, performance scales expensively with the kernel size k. Faster computations can be achieved by kernel decomposition and using constant time one-dimensional algorithms on custom hardware. This paper presents a hardware architecture for real-time computation of running max/min filters based on the van Herk/Gil-Werman (HGW) algorithm. The proposed architecture design uses less computation and memory resources than previously reported architectures when targeted to Field Programmable Gate Array (FPGA) devices. Implementation results show that the architecture is able to compute max/min filters, on 1024×1024 images with up to 255×255 kernels, in around 8.4 milliseconds, 120 frames per second, at a clock frequency of 250 MHz. The implementation is highly scalable for the kernel size with good performance/area tradeoff suitable for embedded applications. The applicability of the architecture is shown for local adaptive image thresholding

Efficient geodesic attribute thinnings based on the barycentric diameter

International audienceAn attribute opening is an idempotent, anti-extensive and increasing operator, which removes from an image connected components which do not fulfil a given criterion. When the increasingness property is dropped, we obtain a - more general - attribute thinning. In this paper, we propose efficient grey scale thinnings based on geodesic attributes. Given that the geodesic diameter is time consuming, we propose a new geodesic attribute, the barycentric diameter to speed up the computation time. Then, we give the theoretical error bound between these two attributes, and we note that in practice, the barycentric diameter gives very similar results in comparison with the geodesic diameter. Finally, we present the algorithm with further optimisations, to obtain a 60× speed up. We illustrate the use of these thinnings in automated non-destructive material inspection: the detection of cracks. We discuss the advantages of these operators over other methods such as path openings or the supremum of openings with segments

Arquiteturas de hardware para aceleração de algoritmos de reconstrução morfológica

Este trabalho apresenta um estudo da implementação de algoritmos para a reconstrução morfológica de imagens bio-medicas em FPGAs (Field Programmable Gate Arrays). As arquiteturas foram baseadas nos algoritmos Sequential Reconstruction (SR) e Fast Hybrid (FH) usando linguagem de descrição de hardware VHDL (Very High Description Language). A metodologia para avaliar a plataforma consistiu em verificar a arquitetura projetada no QuestaSim, fornecendo como dados de entrada as imagens a ser reconstruídas. Adicionalmente, a validação dos resultados da arquitetura foi feita usando linguagem C ou Matlab (usando a função imreconstruct). Além disso, um estudo consumo de recursos de hardware para diferentes tamanhos e conteúdos de imagens foram realizados com o intuito de verificar a aplicabilidade dos algoritmos em arquiteturas reconfiguráveis. Neste trabalho, para a aceleração do processo de reconstrução da imagem foi proposta uma arquitetura reconfigurável baseada no algoritmo FH junto com um algoritmo de aprendizagem de máquina, especificamente uma máquina de vetores de suporte (SVM). Para o treinamento da SVM foi usada uma metodologia de verificação/validação obtendo aproximadamente 20.000 dados de treinamento. Finalmente, foi implementada uma arquitetura que particiona a imagem original em quatro unidades de processamento, processando cada unidade em paralelo. O sistema final implementado fornece um pixel processado por cada ciclo de relógio, depois de um tempo de latência, sendo aproximadamente 8 vezes mais rápida que sua versão não particionada. Adicionalmente, foram feitas comparações rodando os algoritmos de reconstrução morfológica em um processador ARM embarcado dentro do FPGA.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES).This work presents a study of the implementation of algorithms for the morphological reconstruction of bio-medical images in FPGAs (Field Programmable Gate Arrays). The architectures were based on Sequential Reconstruction (SR) algorithms and Fast Hybrid (FH), using VHDL (Very High Description Language). The methodology for the evaluation of the platform consisted of verifying the architecture designed in QuestaSim, providing the images to be reconstructed as input data. Additionally, the validation of the results of the architecture was made using C or Matlab languages (using the imreconstruct function). Additionally, a study of hardware resource consumption for different sizes and content of images was conducted, in order to verify the applicability of the algorithms in reconfigurable architectures. In this work, in order to accelerate the image reconstruction process, a reconfigurable architecture based on the FH algorithm is proposed together with machine learning, specifically a support vector machine (SVM). For the SVM training a verification/validation methodology was used, obtaining approximately 20,000 training data. Finally, an architecture was implemented that partitions the original image in four processing units, processing each unit in parallel. The final system implemented provides one pixel processed for each clock cycle, after a latency time, being approximately 8 times faster than its unpartitioned version. Lastly, comparisons were made by running the morphological reconstruction algorithms in an ARM processor embedded within the FPGA

Projections et distances discrètes

Le travail se situe dans le domaine de la géométrie discrète. La tomographie discrète sera abordée sous l'angle de ses liens avec la théorie de l'information, illustrés par l'application de la transformation Mojette et de la "Finite Radon Transform" au codage redondant d'information pour la transmission et le stockage distribué. Les distances discrètes seront exposées selon les points de vue théorique (avec une nouvelle classe de distances construites par des chemins à poids variables) et algorithmique (transformation en distance, axe médian, granulométrie) en particulier par des méthodes en un balayage d'image (en "streaming"). Le lien avec les séquences d'entiers non-décroissantes et l'inverse de Lambek-Moser sera mis en avant

Advanced Operation and Maintenance in Solar Plants, Wind Farms and Microgrids

This reprint presents advances in operation and maintenance in solar plants, wind farms and microgrids. This compendium of scientific articles will help clarify the current advances in this subject, so it is expected that it will please the reader