generating matrix randomly

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

Answer 1

[Junaid]

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.

Answer 2

[Junaid]

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.

[kash]

thank u juniard ,how to read the image from those final pixels

[kash]

Juniard like this i need 6 matrices ,where the pixels are intercganged

[Walter Roberson]

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]

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]

I am having trouble figuring out what you are trying to do, sorry.

[kash]

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]

I wouldn't expect any of them to have good clarity compared with the original image.