Now a days, Researchers exploit different transforms other than DCT, DFT etc. Recent papers of contourlet transform Stganography: 1. https://link.springer.com/article/10.1007%2Fs12065-020-00387-8

2. Article Digital image watermarking based on angle quantization in di...

3. Lah tranform based steganography:: Article Application of Lah transform for security and privacy of dat...