说明：  各种变换：// FFT() - 一维快速付立叶变换 // IFFT() - 一维快速付立叶逆变换 // Fourier() - 二维快速傅立叶变换 // IFourier() - 二维快速傅立叶逆变换 // DCT() - 一维快速离散余弦变换 // IDCT() - 一维快速离散余弦逆变换 // FreqDCT() - 二维快速离散余弦变换 // IFreqDCT() - 二维快速离散余弦逆变换，图象的二维离散小波变换
(Various transformations:// FFT ()- one-dimensional Fast Fourier Transform// IFFT ()- one-dimensional inverse fast Fourier transform// Fourier ()- two-dimensional fast Fourier transform// IFourier ()- D Inverse Fast Fourier Transform// DCT ()- one-dimensional fast discrete cosine transform// IDCT ()- Fast one-dimensional inverse discrete cosine transform// FreqDCT ()- two-dimensional fast discrete cosine transform// IFreqDCT ()- two-dimensional fast inverse discrete cosine transform, discrete wavelet transform two-dimensional image)