Ponencia
Multi-resolution low-power Gaussian filtering by reconfigurable focal-plane binning
Autor/es | Fernández Berni, Jorge
Carmona Galán, Ricardo Pozas Flores, Francisco Zarandy, A. Rodríguez Vázquez, Ángel Benito |
Departamento | Universidad de Sevilla. Departamento de Electrónica y Electromagnetismo |
Fecha de publicación | 2011 |
Fecha de depósito | 2019-09-20 |
Publicado en |
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ISBN/ISSN | 9780819486578 |
Resumen | Gaussian filtering is a basic tool for image processing. Noise reduction, scale-space generation or edge detection are examples of tasks where different Gaussian filters can be successfully utilized. However, their ... Gaussian filtering is a basic tool for image processing. Noise reduction, scale-space generation or edge detection are examples of tasks where different Gaussian filters can be successfully utilized. However, their implementation in a conventional digital processor by applying a convolution kernel throughout the image is quite inefficient. Not only the value of every single pixel is taken into consideration sucessively, but also contributions from their neighbors need to be taken into account. Processing of the frame is serialized and memory access is intensive and recurrent. The result is a low operation speed or, alternatively, a high power consumption. This inefficiency is specially remarkable for filters with large variance, as the kernel size increases significantly. In this paper, a different approach to achieve Gaussian filtering is proposed. It is oriented to applications with very low power budgets. The key point is a reconfigurable focal-plane binning. Pixels are grouped according to the targeted resolution by means of a division grid. Then, two consecutive shifts of this grid in opposite directions carry out the spread of information to the neighborhood of each pixel in parallel. The outcome is equivalent to the application of a 3×3 binomial filter kernel, which in turns is a good approximation of a Gaussian filter, on the original image. The variance of the closest Gaussian filter is around 0.5. By repeating the operation, Gaussian filters with larger variances can be achieved. A rough estimation of the necessary energy for each repetition until reaching the desired filter is below 20nJ for a QCIF-size array. Finally, experimental results of a QCIF proofof- concept focal-plane array manufactured in 0.35μm CMOS technology are presented. A maximum RMSE of only 1.2% is obtained by the on-chip Gaussian filtering with respect to the corresponding equivalent ideal filter implemented off-chip. |
Identificador del proyecto | 2006-TIC-2352
TEC 2009-11812 N000141110312 |
Cita | Fernández Berni, J., Carmona Galán, R., Pozas Flores, F., Zarandy, A. y Rodríguez Vázquez, Á.B. (2011). Multi-resolution low-power Gaussian filtering by reconfigurable focal-plane binning. En V Bioelectronics, Biomedical, and Bioinspired Systems V and Nanotechnology (806806-1-806806-9), Praga, República Checa: The International Society for Optics and Photonics. |
Ficheros | Tamaño | Formato | Ver | Descripción |
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Multi-resolution low-power.pdf | 3.002Mb | [PDF] | Ver/ | |