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:
- 2-Level DWT: Use 2-level DWT to decompose the image, providing detailed frequency analysis for better data embedding in less noticeable areas.
- 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.
- 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.
- 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.
