Data/hora: 24/06/2024 11:12:19

Biblioteca(s): 	Embrapa Instrumentação.	
Data corrente: 	22/12/1999	
Data da última atualização: 	22/12/1999	
Autoria: 	MASCARENHAS, N. D. A.; SANTOS, S. S. L.; CRUVINEL, P. E.	
Afiliação: 	UFSCar; EMBRAPA-CNPDIA.	
Título: 	The use of MAP estimation techniques in the tomographic reconstruction of poisson noise corrupted images.	
Ano de publicação: 	1996	
Fonte/Imprenta: 	In: SIMPOSIO BRASILEIRO DE COMPUTACAO GRAFICA E PROCESSAMENTO DE IMAGENS, 9., out. 1996, Caxambu, MG. Anais do SIBGRAPI 96. Caxambu: SBC/UFMG, 1996.	
Páginas: 	p. 197-204.	
Idioma: 	Inglês	
Conteúdo: 	The problem of tomographic image reconstruction is important in many areas of applied science and technology. This work presents new methods for the tomographic reconstruction of images with poisson noise corrupted projections. The poisson noise comes from the discrete nature of radiation that characterizes the counting process of particles in the projection set. The reconstruction method is performed by first filtering the noisy projections under the maximum a posteriori criterion and subsequently reconstructing the images through conventional filtering-backprojection methods using the ramp filter. The "a priori" knowledge is incorporated by using several densities, including the Gaussian and densities defined on the non-negative real line. These densities were used to denote the fact that the rates of counting on the projections are non-negative quantities. Experimental results include the filtering of simulated noisy projections and the reconstruction of simulated and real phantoms scanned with a minitomograph scanner for soil science. The obtained results indicate that, by using the MAP criterion, it is possible to obtain a lower mean square error in reconstruction, as compared to conventional methods of filtering-backprojection, with a very small increase in computational effort.	
Palavras-Chave: 	Agricultural instrumentation; Imagem; Instrumentacao agropecuaria; MAP; Noise; Poison; Reconstrucao; Reconstruction; Techniques; Tecnicas.	
Thesagro: 	Ruído; Tomografia.	
Thesaurus Nal: 	tomography.	
Categoria do assunto: 	--	
Registro original: 	Embrapa Instrumentação (CNPDIA)	
Exemplares: 	CNPDIA - (5577-1) - UPC - SP - -- - PROCI-96.00126 -  - 1996.00126 - DIS