which dct and dwt techniques are best suited for image steganography when using combination of dwt and dct?

which dct and dwt techniques are best suited for image steganography when using combination of dwt and dct?

Answer 1

[Karanjot]

Hi Jasmine,

Your query is probably resolved but I am posting this answer as a reference for the community.

For effective image steganography using a combination of DWT and DCT in MATLAB, consider the following:

1. 2-Level DWT: Use 2-level DWT to decompose the image, providing detailed frequency analysis for better data embedding in less noticeable areas.
2. Block-Based DCT: Apply DCT on the low-frequency (LL) sub-band from the DWT decomposition, as it retains critical image features and is less sensitive to changes.
3. Embedding in Middle Frequencies: Embed the secret data in the middle-frequency DCT coefficients. This maintains a balance between being imperceptible to the human eye and robust against distortions.
4. Coefficient Selection: Choose coefficients that are neither too small (to avoid distortion) nor too large (to ensure imperceptibility).

This approach enhances both robustness and invisibility in your steganographic system.