Image steganography using vector quantization and discrete cosine transform

Abstract

Application of the camouflaging technique achieves the goal of secure communication for secret images. The camouflaging technique in image, proposed by this article, combines lossy image compression technique vector quantization (VQ), lossless data compression and the cryptographic encryption/decryption procedure to decrease its deeply embedded secret data and increase its level of security. At last, the secret data are hidden in the frequency coefficients of the discrete cosine transform (DCT) domain of the cover image. There are two advantages of this proposed method: (a) The required secret data to be embedded by using VQ compression are less than the original and the time consumption to recover the secret image is more efficient, providing that the image quality is still visually satisfactory after restoration of the image, (b) If the stego-image had least-significant-bit malfunctioned, the secret image would still be distinguishable after restoring it from the damaged stego-image.

Keywords:

• steganography
• vector quantization
• discrete cosine transform (DCT)