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Hi, I want a 2d array of rows and columns filled with floating point numbers (matrix) which can be converted to a grayscale image.

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Anvinder  Singh
Anvinder Singh on 25 Feb 2016
Answered: Cam Salzberger on 29 Feb 2016
Should i use the mat2gray function of matlab ? I want to program my own image and fill it with numbers.
  4 Comments
Anvinder  Singh
Anvinder Singh on 25 Feb 2016
Thanks Walter. So is it possible to use multiple loops in the same matrix to have different pixels ? I mean instead of one repmat i need multiple repmats for the same matrix A.

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Answers (1)

Cam Salzberger
Cam Salzberger on 29 Feb 2016
Hello Anvinder,
I understand that you are looking to display a grayscale image based on values from a matrix. As jgg said, "mat2gray" helps in ensuring that the matrix values get scaled appropriately (between 0 and 1) to display the full range in an image.
You don't need to use "repmat" to create the grayscale image, that was just an example. Here's an example that uses loops to allow for calculating each pixel value:
nRows = 10;
nCols = 15;
A = zeros(nRows,nCols);
for r = 1:nRows
for c = 1:nCols
A(r,c) = r+c/2;
end
end
I = mat2gray(A);
imshow(I)
I hope this helps!
-Cam

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