generating matrix randomly

2012 1 3
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I have an matrix of an image ,face.jpg,now i want to interchange the pixel values,position of values must be changed( randomly),,please help

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Junaid
Junaid 2012-1-3

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Dear What I understand is you will randomly swap the pixel values of images 6 times. At the end you will have 6 images. Again multiple ways to do it. Here is one example.
myface = imread('myface.jpg'); % this is your image
myface1 = myface; % just to keep the copy of original
for i=1:6 % this decides how many times you want to repeat
myRan = randperm(prod(size(myface))); % we assume myface.jpg is grayscale
myRan=reshape(myRan,size(myface));
myface(myRan) = myface;
myimageset{i} = myface;
myface = myface1;
end
Now you have six images in myimageset. You can get image by myimageset like this.
image1 = myimageset{1};
you can put myimageset in loop and display each image to see your output. The code I have written is not optimal. The computation speed can be improved. I did this way to divide the process into step so that you can follow what actually is happening.

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Junaid
Junaid 2012-1-3

1 个投票

There are many ways to do it. One possible way is.
myface = imread('myface.jpg');
myRan = randperm(prod(size(myface))); % we assume myface.jpg is grayscale
myRan=reshape(myRan,size(myface));
myface(myRan) = myface;
These four lines can be done in one line. Just to show you the steps i followed this into four lines.

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kash
kash 2012-1-3
thank u juniard ,how to read the image from those final pixels
kash
kash 2012-1-3
Juniard like this i need 6 matrices ,where the pixels are intercganged
Walter Roberson
Walter Roberson 2012-1-3
You would need to know the myRan permutation vector in order to reverse the transformation. This is known as the Key Exchange Problem, http://en.wikipedia.org/wiki/Key_exchange#The_key_exchange_problem
kash
kash 2012-1-3
Thanks walter i went through it ,i ment i need to read the image from those final pixels,the may may contain whatever it may,like these i want to generate 6 marices and check which matrix values give as near as the original image
Walter Roberson
Walter Roberson 2012-1-3
I am having trouble figuring out what you are trying to do, sorry.
kash
kash 2012-1-3
Walter here are the steps
1.need to take an image
2.need to interchange the coefficient (randomly) 6 times
3.now i get 6 matrices (no 2 coefficient must be same)
4.from this i need to get 6 images
5.finally need to check which has good clarity compared with original image
Walter Roberson
Walter Roberson 2012-1-3
I wouldn't expect any of them to have good clarity compared with the original image.

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