Estimation and Detection of Images Degraded by Film-Grain Noise
Abstract
One goal of this study has been to use the theoretical and experimental results on film characteristics obtained by photographic scientists in order to define film-grain noise within the context of estimation theory. A detailed model for the overall photographic imaging system is presented. There are linear blurring effects at the initial and the final segments of this model to account for various optical and chemical degradations. The middle segment of the model represents signal dependence effects of film-grain noise and includes a nonlinear noise term. The accuracy of this model is tested by simulating images according to it and comparing the results to images of similar targets that were actually recorded on film. These comparisons point out that the model is a good representation of the photographic imaging system. The restoration of images degraded by film-grain noise is considered in two different contexts - estimation theory and detection theory. Under the topic of estimation, a discrete Wiener filter is developed which explicitly allows for the signal- dependence of the noise. The filter adaptively alters its characteristics based on nonstationary first order statistics of an image. This filter is shown to have an advantage over the conventional Wiener filter.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1976
- Accession Number
- ADA122438
Entities
People
- Firouz Naderi
Organizations
- University of Southern California