error in writing values to text file

I have a code below

clc
clear all
close all
% a= imread('im16_1a.png');
% I=rgb2gray(a);
I=imread('rice.png');
imgTrans = I';
% iD conversion
img1D = I(:);
% Decimal to Hex value conversion
imgHex = dec2hex(img1D,6);
% New txt file creation
fid = fopen('text.txt', 'wt');
% Hex value write to the txt file
fprintf(fid,'%s\n',imgHex)
% Close the txt file
fclose(fid)
winopen('text.txt')

i this i have converted to hexadecimal,i want to write values in imgHex to text file,but wen i write i dont get vales as in imgHex,kindly help

Answer 1

[Guillaume]

dec2hex returns a single 2d string which is then flattened by column into a 1d string in the call to fprintf. You have several options. one is to iterate over the rows of the 2d string and call fprintf on each row:

for hexrow = 1:size(imgHex, 1)
  fprintf(fid, '%s\n', imgHex(hexrow, :));
end

Another is:

cellfun(@(hexstring) fprintf(fid, '%s\n', hexstring), num2cell(imgHex, 2));