Paper Title
Performance Analysis of Frequency Domain Steganography using Z Transform (ZT) and Discrete Cosine Transform (DCT)
Abstract
Image steganography, often known as information concealment, is a kind of art. This proposal makes use of the Z
transform (ZT) and Discrete Cosine Transform (DCT) to present a transformed domain based grey scale picture
authentication/data concealment method called SIFDZT and SIFDDCT. Z-Transform is used to convert the original sub
image (cover image) block to its matching frequency domain. It is applied to the source image's 2x2 masks in a row major
fashion. Based on the mask's median value, one bit of the concealed image is inserted in each source picture's mask onto the
fourth LSB of the transformed coefficient. For proper decoding, a delicate handling has also been carried out as a postembedding
procedure. The final stage in embedding a mask is to reverse convert the stego sub image. Before the message or
hidden image's content is inserted, the hidden image's dimensions are added during the embedding process. The decoding
process is conducted in reverse. A signal or image is transformed from the spatial domain to the frequency domain using the
DCT. It divides the image into components (or spectral sub-bands) of varying significance (in terms of the visual quality of
the image). It can divide an image into components with high, middle, and low frequencies .High PSNR results for a variety
of photos are consistent with the SIFDZT and SIFDDCT watermark's invisibility standards.
Keywords - Frequency Domain Steganography, Invisible Watermark, Peak Signal to Noise Ratio (PSNR), Z
Transform(ZT), Median Based Embedding in frequency Domain, Discrete Cosine Transform(DCT).