Bilinear interpolation can be implemented with only three multiplication and
six add/subtract operations per pixel and thus is only slightly more computa-
tionally expensive than nearest-neighbor interpolation [1]. It guarantees that the
interpolated function will be continuous at the boundaries between pixels, but it
does not avoid slope discontinuities. In many cases this is not a serious flaw.
5.3.3 Bicubic Interpolation
With bicubic interpolation, the interpolated surface not only matches at the
boundaries between pixels, but has continuous first derivatives there as well. The
formula for the interpolated surface is
px, yðÞ¼
X
3
i¼0
X
3
j¼0
a
ij
x
i
y
j
(5:5)
The 16 coefficients a
ij
are chosen to make the function and its derivatives
continuous at the corners of ...