i had converted image into blocks. I converted blocks to linear array. Next i calculated mean values for first 8 arrays as given below. now i want to convert mean values to linear array again. please send suitable code. please don't ignore it. help .

for i=1:4:16

      for j=1:4:16

        block=I(i:i+3,j:j+3);

        %convert 4X4 into 16X1 column vector
        tv(:,col)=reshape(block,16,1);

        col=col+1;
        count=count+1;
        column=column+4;

      end

     row=row+4;

end

%find mean of 8 arrays
nn=8; 
for count=1:16
    sum1=sum1+tv(:,count);
if count==nn*nnn
        cv(:,r)=sum1/8;
        sum1=0;
       nnn=nnn+1;
       r=r+1;
end
end

[Star Strider]

You cannot un-fry that egg.

Calculating a mean — even with the standard deviation — requires that you throw away information that you can never again retrieve. The best you can hope for is a vector the same size as the original, every element being the mean.

[sri raj]

thank u sir

Answer 1

[Walter Roberson]

Your code does not calculate mean values -- not unless nnn happens to equal 1, and for some odd reason you only want the first 8 values to be included even though your loop goes to 16.

[sri raj]

sir, please send code to calculate mean for first 8 arrayys and also reverse of it. ie, linear array->mean->linear array. please help me sir

[Walter Roberson]

mean8 = mean(tv(:,1:8), 2);

You cannot go back to the original values; at most you can make copies of the mean

repmat(mean8, 1, 8)

[Image Analyst]

You already have the "linear array". You didn't use clear or clearvars, did you? So you still have it and there is no reason to "go back to it" from the mean when you already have it. Simply use what you've got.

[sri raj]

thank you so much sir..

[sri raj]

sir.. please can u say code for standard deviation for first 8 arrays as above (mean)

[Image Analyst]

I don't know what you mean. Walter already gave the same answer as I would given to what you just asked:

mean8 = mean(tv(:,1:8), 2);

so if you don't want that, then what do you want?

[sri raj]

sir. i accepted your answer. and another clarification. i have linear arrays. i want to know the code for standard deviation for first 8 arrays only. so please can you send the code.. thank you sir

[Image Analyst]

If you're in a loop, just have the upper limit be 8 and it will only do 8

for blockNumber = 1 : 8
    % code
    stdDev(blockNumber) = std(............
end

[sri raj]

thank you sir..

Answer 2

[Image Analyst]

Exactly what values are you hoping to have in this second linear array? If you want the first ones, simply use the original values

secondLinearArray = firstLinearArray;

If you want the means, then use repmat, imresize, or other approaches to create it from your means, for example

secondLinearArray = theMean * ones(size(firstLinearArray));