22-01-2013, 01:14 PM
A NEW SCHEME FOR INFORMATION HIDING BASED ON DIGITAL IMAGES
1A NEW SCHEME.pptx (Size: 434.24 KB / Downloads: 23)
INTRODUCTION
Digital steganography is a way of hiding the existence of secret message under the cover of a carrier signal in such a way that no one apart from the sender and intended recipient even realizes there is a hidden message.
PHASES IN THIS SCHEME
Firstly, take 8-bit gray-scale digital image and the binary secret message.
Secondly, segment the given cover image into non-overlapping pixel-groups contains seven pixels each.
Thirdly, try to embed the first seven secret bits into the first pixel-group of seven pixels.
Embedding operation is successful set flag[k]=10;
If not, try to embed the first three secret bits into that pixel-group once again, if none of the wet pixels is altered this time, operation is successful and flag[k]=01;
EVALUATION CRITERIONS
Two important evaluation criterions to measure the performance of a steganographic scheme
Embedding efficiency (embedding quality or visual quality) of the stego image.
Embedding payload (embedding capacity) of the cover image.
Embedding efficiency
PSNR to evaluate the degree of similarity between a stego image and its original image.
CONCLUSION
Based on digital images, we proposed a new scheme for information hiding. By introducing the WPC method into the steganographic scheme to improve its embedding efficiency and using selectable operations of embedding to avoid the fails of embedding and assure the embedding payload. Specially, our scheme gives some degree of security by considering the selectable operations as the two fold safeguards.