What is interpolation?
Interpolation is defined by the authors of our book as the fitting of a continuous signal to a set of sample values, and is a commonly used procedure to reconstruct a function from its samples.
Types of interpolation
Zero order interpolation:
In this type of interpolation the function holds its current value until the next sample is taken. A good example of this is a series of step functions.
First order interpolation:
In this type of interpolation the samples are connected by a straight line. An example of this is a series of ramp functions.
N-th order interpolation:
In this type of interpolation the samples are connected with a n-th order function. For example with 2nd order interpolation the samples would be connected with a quadratic function.
As the order of the interpolation increases the reconstruction of the CT signal from the sampled signal approximates the original CT signal better.
