Determination of the Effects of Defocus and Information Content.
Abstract
The concept of signal-to-noise power spectrum description of photographic imagery is extended to include transfer function losses and information content. A coherent optical processor is used for quantifying image content. Experiments show that theoretical predictions are verified. The determination of the objective level of quality or information content of technical photography is a subject of much interest. The use of specific targets for the production of numeric data, such as resolution or modulation transfer factor, is applicable only in cases where the original object is available for attaching a particular target. In many cases the desired general image description must be obtained from the natural imagery collected on the photographic negative. The use of a coherent optical processor for carrying out this measurement is a useful approach. Such applications are not novel, in that several authors have reported on this approach. In the Shannon and Cheatham work, a method of describing the OPS characteristics by use of a 'signal-to-noise power spectrum' method was developed. This concept, referred to as the SNPS function, succeeded in compressing the huge dynamic range of the observed image signal and the photographic and processor noise into a relatively simple function.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1978
- Accession Number
- ADA095078
Entities
People
- R. R. Shannon
- S. Sagan
Organizations
- University of Arizona