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Second Order Coherent Power Spectra, Brian A. Gorin
Second Order Coherent Power Spectra, Brian A. Gorin
Theses
The relationship between second order stochastic processes and coherent power spectra are explored for developed grain size frequency distributions of silver halide emulsion/developer combinations. Although Wiener spectra represent incoherent power spectra, the coherent case has been unresolved due to the difficulty of filtering the optical system effect. The emulsion plates were exposed with a uniform irradiance distribution from an incoherent tungsten source to create a series of uniform density samples. Conventional processing chemistry is utilized with substitution of different developer types, from predominantly physical development to direct chemical development. The exposed and processed density samples were liquid gated with refractive …
Perception Of Graininess In Complex Photographic Images Through Objective And Subjective Comparison, Glenn E. Mcneill
Perception Of Graininess In Complex Photographic Images Through Objective And Subjective Comparison, Glenn E. Mcneill
Theses
A model previously used for the perception of graininess in uniform-density images that exist in electrophotography, has been verified for use in silver-halide photography. In addition, a model has been developed which estimates the sensation of graininess in photographic images of non -uniform density. Given the relationship between graininess and density in uniform-density images, the graininess in a complex image is weighted by the frequency of occurrence of each measured density in the image. Such an analysis is compared to subjective evaluations. It is shown that the graininess model is useful in predicting the sensation of graininess in photographs.