Spatial resolution properties of penalized-likelihood image reconstruction: space-invariant tomographs
- 1 September 1996
- journal article
- Published by Institute of Electrical and Electronics Engineers (IEEE) in IEEE Transactions on Image Processing
- Vol. 5 (9) , 1346-1358
- https://doi.org/10.1109/83.535846
Abstract
This paper examines the spatial resolution properties of penalized-likelihood image reconstruction methods by analyzing the local impulse response. The analysis shows that standard regularization penalties induce space-variant local impulse response functions, even for space-invariant tomographic systems. Paradoxically, for emission image reconstruction, the local resolution is generally poorest in high-count regions. We show that the linearized local impulse response induced by quadratic roughness penalties depends on the object only through its projections. This analysis leads naturally to a modified regularization penalty that yields reconstructed images with nearly uniform resolution. The modified penalty also provides a very practical method for choosing the regularization parameter to obtain a specified resolution in images reconstructed by penalized-likelihood methods.Keywords
This publication has 31 references indexed in Scilit:
- Bias-variance trade-offs analysis using uniform CR bound for imagesPublished by Institute of Electrical and Electronics Engineers (IEEE) ,2002
- Exploring estimator bias-variance tradeoffs using the uniform CR boundIEEE Transactions on Signal Processing, 1996
- Mean and variance of implicitly defined biased estimators (such as penalized maximum likelihood): applications to tomographyIEEE Transactions on Image Processing, 1996
- Precision and accuracy of regional radioactivity quantitation using the maximum likelihood EM reconstruction algorithmIEEE Transactions on Medical Imaging, 1994
- Noise properties of filtered-backprojection and ML-EM reconstructed emission tomographic imagesIEEE Transactions on Nuclear Science, 1993
- A generalized Gaussian image model for edge-preserving MAP estimationIEEE Transactions on Image Processing, 1993
- Preconditioning methods for improved convergence rates in iterative reconstructionsIEEE Transactions on Medical Imaging, 1993
- Spatial Resolution Properties of FB and ML-EM Reconstruction MethodsPublished by Institute of Electrical and Electronics Engineers (IEEE) ,1993
- Object-dependent performance comparison of two iterative reconstruction algorithmsIEEE Transactions on Nuclear Science, 1988
- Quantitation in Positron Emission Computed TomographyJournal of Computer Assisted Tomography, 1982