Relationships between Convolution and Correlation for Fourier Transform and Quaternion Fourier Transform

In this paper we introduce convolution theorem for the Fourier transform (FT) of \ud two complex functions. We show that the correlation theorem for the FT can be \ud derived using properties of convolution. We develop this idea to derive the \ud correlation theorem for the quaternion Fourier transform (QFT) of the two \ud quaternion functions