The power in components of the image (F) with a wave number less than a user specified value (g) is set to zero (except that there remains a 128 intensity offset).
{ 128, |k| = 0
F' = { 0 0 < |k| < g
{ F, |k| >= g
The power in components of the image (F) with a wave number
greater than a user specified value (g) is set to zero.
{ F, |k| <= g
F' = {
{ 0, |k| > g
M The power in components of the image (F) for wave numbers greater than a
user specified value (g) is multiplied by the wave number excess raised to some user specified exponent (r). If the exponent is positive, then M is a high pass filter. If the exponent is negative, then M is a low pass filter.
{ F, |k| <= g
F' = {
{ F*(|k|-g)**r, |k| > g
The power (F) in wave numbers exceeding some user specified
limit (g) is decreased by a factor related to the wave number excess such that the factor decreases from one to zero.
{ F, |k| <= g
F' = {
{ F*(255-|k|)/(255-g), |k| > g