Relationships between Pixel Count, Aliasing, and Limiting Resolution in Digital Motion Picture Systems

Abstract

This paper analyzes how pixel count affects one type of aliasing artifact and image rendition near limiting resolution. A previous paper 1 showed that aliasing artifacts take many forms. This paper focuses on the aliasing artifact identified in the ISO 12233 standard and identified as Type A aliasing in the prior paper. A relationship termed Type A aliasing equation is presented, which predicts aliasing as measured by the ISO 12233 standard. It is then demonstrated that this equation predicts the best unreconstructed aliasing performance for digital motion picture systems and subsystems, thereby defining one characteristic of an ideal system. The predicted result is then compared by the Type A aliasing equation and the measured aliasing performance of 20 different digital motion picture systems and subsystems. It is also shown that the Type A aliasing equation is superior to the classical Nyquist theory as a predictor of aliasing performance of digital motion picture systems. Finally, the equation is used to compute the minimum number of pixels required for a given aliasing level and limiting resolution, and data is presented to determine the pixel count required to render a given limiting resolution.