Definition - What does Interpolation mean?
Interpolation is the estimation of a value or set of values based on their context. Linear interpolation, a very simple form of interpolation, is basically the rendering of a straight line between two or more points. Interpolation is useful for filling in missing data, such as in upscaling images or creating statistical models.
Techopedia explains Interpolation
Over the years, interpolation has been implemented in many different technologies, including telegraph transmission and digital imaging. Computer-aided design commonly employs spline interpolation in order to render curves that appear organic and are relatively simple to manipulate. Audio interpolation uses mathematical functions to fill in audio data in order to improve sound quality. Some cameras, in addition to optical zoom (which depends on physical lens functions), also feature digital zoom that essentially upscales images through interpolation.