Wrote

Just an utility for work with JPG and Fourier transforms.

Thanks Alvaro, most interesting.
Just different than the Mathcad model in demo added.
The all thing is around Fourier DCT-II [Cosine transform].
JPEG consists in eliminating the diagonal of the image details,
or simply minimizing influence along the diagonal.
DCT-II works well in Smath, as applied otherwise.

Cheers ... Jean

Pattern ZigZag JPEG.sm (190 KiB) downloaded 42 time(s).

Smath Code dct2(f) ... idct2(g)

Fourier DCT-II Smath CODE.sm (38 KiB) downloaded 51 time(s).

PLUGIN UPDATED SMath Studio 0.99.7561 and later

• fixed ifftshift() issues with vectors;
  
• plugin migrated to .NET Core 2 and .NET Standard 2;