dct function
DCT performs a forward or inverse discrete Cosine transform of 1D or 2D array.
For further details, please see: https://docs.opencv.org/master/d2/de8/group__core__array.html#ga85aad4d668c01fbd64825f589e3696d4
Implementation
Mat dct(InputArray src, {OutputArray? dst, int flags = 0}) {
dst ??= Mat.empty();
cvRun(() => cffi.Mat_DCT(src.ref, dst!.ref, flags));
return dst;
}