Special Arguments

Some Convolution and Correlation functions described in this section have two implementations of the algorithm:

• For small data size, function processes data as described by the formula
• For big data size, function uses FFT-inherited algorithms

The optimal algorithm is selected automatically according to the input data size. You can manually choose which algorithm to use by passing one of the following predefined values to the algType parameter of the function:

ippAlgAuto	Select the optimal algorithm automatically.
ippAlgDirect	Use direct algorithm as described by the formula.
ippAlgFFT	Use FFT-based algorithm implementation.

These values are declared in the IppAlgType enumerator.

Several functions support normalization of the output data. You can choose which normalization to apply by passing one of the following values to the function:

ippsNormNone	No normalization (default).
ippsNormA	Biased normalization.
ippsNormB	Unbiased normalization.

These values are declared in the IppsNormOp enumerator.