can i get code for image encryption/decryption

i require code for picture encryption/decryption process.

can any one provide.........

[Walter Roberson]

AES is one of the encryption systems that we absolutely may not discuss code for, due to legal reasons.

[Walter Roberson]

No, using a random phrase key exceeds the legal limits imposed by the USA Department of Commerce as to what encryption theory or encryption code it is legal to discuss without pre-approval of the topic limits and list of participants by that department. The encryption code I posted below is at the outer limits of what can be posted here, and I have always worried whether I in fact exceeded the limits. In some countries it would be enough to get me arrested these days.

Answer 1

[Image Analyst]

We don't get into detailed complicated algorithm. You can check out the literature and choose your own algorithm. See VisonBib: http://iris.usc.edu/Vision-Notes/bibliography/contentschar.html#OCR,%20Document%20Analysis%20and%20Character%20Recognition%20Systems, particularly these sections:

23.3.8 Image Hiding, Data Hiding, Steganography, Steganalysis  
    23.3.8.1 Data Hiding, Steganography, LSB, Least Significant Bit
    23.3.8.2 Halftone Images, Compressed Images: Image Hiding, Data Hiding, Steganography
    23.3.8.3 Surveys, Image Hiding, Data Hiding, Steganography 

23.3.9 Watermarks for Copyright, Ownership Protection, Authentication, Verification, Forgery  
    23.3.9.1 Tamper Detection
    23.3.9.2 Fragile Watermarks
    23.3.9.3 Encryption, Visual Cryptography, Authentication 

23.3.10 Watermarks: Extraction, Detection or Recovery
23.3.11 Watermarks in Video and Multi-Media, Other Data  
    23.3.11.1 Video Data Hiding, Data Hiding in Video, Video Steganography

You will find citations to papers there that you can review to find an algorithm that you want to try. Good luck. Come back here if you have MATLAB questions (instead of algorithm questions, unless they're really simple like how to improve program flow).

Answer 2

[Walter Roberson]

The input for cryptographic algorithms is generally not plain text. If you do happen to have such an algorithm on hand, you could use base64 encoding or uuencoding (the two are very similar) to represent the input as plain text.

(Note: we will not be able to discuss details of non-trivial cryptographic routines here for legal reasons. We can, though, mention use of cryptographic routines if we do not discuss implementation or the theory of how they work.)

Answer 3

[Walter Roberson]

Encryption code, for a vector of uint8:

outvector = invector + 1;
outvector(invector == 255) = 0;

Decryption code, for a vector of uint8:

outvector = invector - 1;
outvector(invector == 0) = 255;