Linear Interpolation

Linear interpolation works by effectively drawing a straight line between two neighboring samples and returning the appropriate point along that line.

More specifically, let be a number between 0 and 1 which represents how far we want to interpolate a signal between time and time . Then we can define the linearly interpolated value as follows:

For , we get exactly , and for , we get exactly . In between, the interpolation error is nonzero, except when happens to be a linear function between and .

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Subsections

• One-Multiply Linear Interpolation
• Fractional Delay Filtering by Linear Interpolation

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About the Author: Julius Orion Smith III
Julius Smith's background is in electrical engineering (BS Rice 1975, PhD Stanford 1983). He is presently Professor of Music and Associate Professor (by courtesy) of Electrical Engineering at Stanford's Center for Computer Research in Music and Acoustics (CCRMA), teaching courses and pursuing research related to signal processing applied to music and audio systems. See http://ccrma.stanford.edu/~jos/ for details.