Video steganography is a technique used to hide an image within a video file without affecting its visual and auditory quality. It is a form of digital steganography that conceals information within a carrier medium, in this case, a video.
The process involves embedding a secret image into the video frames in a way that it remains undetectable to the human eye. Various methods can be used for this purpose, such as:
- Least Significant Bit (LSB) method: This involves replacing the least significant bits of the video frames with the secret image data. As the least significant bits have minimal impact on the overall video quality, the hidden image can be concealed effectively.
- Transform domain techniques: Mathematical transforms like Discrete Cosine Transform (DCT) or Discrete Wavelet Transform (DWT) can be applied to the video frames. The secret image is embedded in the transformed coefficients, which can later be inverse-transformed to extract the hidden image.
- Motion vector-based techniques: By slightly modifying the motion vectors already present in the video, the secret image can be hidden. This method takes advantage of the motion information between frames to embed the image.
Once the video with the hidden image is received, the recipient needs to know the specific algorithm or key used for embedding to extract the hidden image successfully.
Video steganography with hidden images can have both legitimate and potentially malicious applications. It is essential to use this technique responsibly, adhering to legal and ethical considerations.