How to express the grey-scale image as a twodimensional matrix whose size is M1 x M2.?

Express the grey-scale image watermark as a two dimensional matrix whose size is M1 x M2.

Img = {Img( k,j), 0 ≤ k ≤ M1, 0 ≤ j ≤ M2}

Convert the two-dimensional image matrix Img into a one-dimensional vector W of length M1 x M2.

W = {W(i) = Img (k,j) ,i = k x M2 + j, 0 ≤ k ≤M1, 0≤ j ≤M2}

Answer 1

[Walter Roberson]

W = img(:);

See also reshape()