Resumen de Split and shift methodology: Overcoming hardware limitations on cellular processor arrays for image processing
- English
This thesis addresses the so-called Split and Shift (S&S) methodology. This methodology is intended to deal with the implementation of kernels of sizes that overflow the physically implemented resources (local connections and weighting circuits) on synchronous Cellular Processor Arrays (CPA), including the realization of large neighborhood operations and/or the reduction of the available hardware in order to drop the area consumption. Two main goals are pursed in the development of the methodology, namely 1) minimum penalty at processing time and 2) absolutely no penalty at functional level. The work presents different techniques and guidelines for the methodology application and introduces a Figure of Merit (FoM) to evaluate them by relating area gains with time penalty. Together with a shape analysis over a well known kernel library we propose more adequate weighting circuits configurations and justify the classical choice of NEWS (North-East-West-South) connectivity. To validate the methodology we realize several estimates over actual physical implementations and we propose the realization over CPAs of the spin filters, SIFT (Scale Invariant Feature Transform) and SURF (Speeded-Up Robust Features) algorithms. A more in-depth trade-off analysis is realized over the implementation of the Pixel Level Snakes (PLS) algorithm.
- galego
Na era multimedia, o procesado de imaxe converteuse nun elemento de singular importancia nos dispositivos electrónicos. Dende as comunicacións (p.e. telemedicina), a seguranza (p.e. recoñecemento retiniano) ou control de calidade e de procesos industriais (p.e. orientación de brazos articulados, detección de defectos do produto), pasando pola investigación (p.e. seguimento de partículas elementais) e diagnose médica (p.e. detección de células estrañas, identificaciónn de veas retinianas), hai un sinfín de aplicacións onde o tratamento e interpretación automáticas de imaxe e fundamental. O obxectivo último será o deseño de sistemas de visión con capacidade de decisión. As tendencias actuais requiren, ademais, a combinación destas capacidades en dispositivos pequenos e portátiles con resposta en tempo real. Isto propón novos desafíos tanto no deseño hardware como software para o procesado de imaxe, buscando novas estruturas ou arquitecturas coa menor area e consumo de enerxía posibles sen comprometer a funcionalidade e o rendemento.
