Steganography, which means concealed writing, is the method of hiding secret information into another cover-media, for instance audio, video, image and text, in such a way that the very existence of the information is camouflaged. As opposed to the aim of cryptography, which prevents the data from illicit access and modification by changing the secret data into messy and meaningless bit-streams, the purpose of steganography is to hide their very existence so that the embedded data is inaudible or invisible to the grabbers. Using cryptographic techniques, the transformed secret bit-streams may draw the eavesdroppers’ attention, when using steganographic strategies, the interceptors might not spot the presence of the concealed data. In this study, steganographic techniques for digital images, which are used as a cover-media, are looked into and reviewed…
Contents: Steganographic techniques for digital images
Chapter 1 Introduction
Chapter 2 Overview of Steganography
2.1 General Model for Steganography
2.2 Fundamental Requirements for Steganography
2.2.1 Imperceptibility
2.2.2 Embedding Capacity
2.3 Review of Existing Steganographic Techniques
2.3.1 Data Hiding Techniques Based On LSB Substitution
2.3.2 Data Hiding Techniques for Image Data
2.3.3 Hiding Data in Compressed Image
2.4 Conclusion
Chapter 3 A Steganographic Technique for Data Hiding
3.1 Introduction
3.2 A Steganographic Method for Digital Images using Side Match
3.2.1 Embedding Process
3.2.2 Extraction Process
3.2.3 Problem of the Method
3.3 First Rectified Method
3.4 Second Rectified Method
3.5 Experimental Results
3.5.1 Results of the First Rectified Method
3.5.2 Results of the Second Rectified Method
3.6 Conclusion
Chapter 4 Data Hiding in Images by Dynamic-Length LSB Substitution Based On Pixel-Value Differencing
4.1 Introduction
4.2 Proposed Data Hiding Method
4.2.1 Embedding Process
4.2.2 Extraction Process
4.3 Experimental Results
4.4 Comparison with Two Steganographic Techniques
4.5 Conclusion
Chapter 5 Image Hiding Based On Block Difference
5.1 Introduction
5.2 Preliminary Definitions
5.3 Proposed Image Hiding Method
5.3.1 Embedding Process
5.3.2 Extraction Process
5.4 Storage Requirement for the Block Header Information
5.4.1 Storage Requirement for Reference-Block-Index
5.4.2 Storage Requirement for Quantized-Error-Matrix
5.4.3 Storage Requirement for Minimum Element in the Error-Matrix
5.4.4 Storage Requirement for Difference-Matrix
5.5 Experimental Results
5.6 Comparison with the Image Hiding Method Proposed by Chan et al
5.7 Conclusion
Chapter 6 Conclusions and Future Developments…
Source: City University of Hong Kong