help needed!!! selecting dct coefficients-image watermarking

[dlna]

hi,
im working on a watermarking proj. I want help/code in finding a way to select the middle-frequency range dct coefficients.

i have already broken the image into 8x8 blocks and performed 2dct on each of them.


thanks,

 

[omarakash]

Re: help needed!!! selecting dct coefficients-image watermar

hi..
i am working in the same project.
plz, if u have any code that help i would be appreciate that.
and if u can give me some hints about the watermarking procedures and the DCT2

 

[dlna]

Re: help needed!!! selecting dct coefficients-image watermar

inputDCT=inputDCT';
inputDCT=inputDCT(1:end); % row wise wise vector

midIndexes=[7 8 14 15 21 22 28 29 36 37 43 44 50 51 57 58]; % zig zag

middleFreq=inputDCT(midIndexes);

middleFreq=reshape(middleFreq,4,4);
middleFreq=middleFreq';

this would help.

 

[omarakash]

thanks a lot for replying to me
sorry for disturb,could you plz upload for me some of your work, so i can take advantage of it. i really need it. i am stuck and no time left to submit the project.
Please

Best Regards
~omar