Apparatus and method for the measurement of grain in images
Patent 5709972 Issued on January 20, 1998. Estimated Expiration Date: November 19, 2016. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
A generalized grain ruler incorporating a plurality of uniform patches representing a range of granularities, each patch being a perceptually distinct representation of graininess spaced at perceptually uniform intervals and recorded in an increasing sequence of graininess. A method for producing a generalized grain ruler for the measurement, by comparison of, grain in a reference imaging system generated image, comprising, the steps of:a) generating a set of random numbers for each image component;b) filtering each set of random numbers to alter the Wiener spectrum to result in a filtered set of random numbers that look as if they were generated by the reference photographic system; andc) delivering the filtered set of random numbers to an output device that renders them into an image which is the generalized grain ruler.
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