problem with reading and writing image

NumberOfimages=4;       %chose the number of images you want to give input
prefix_image='data (';    %change the desired input image name here only
fileformat=').tif';       %change the desired input image format here only
for num=1:NumberOfimages
  I = imread(strcat(prefix_image,num2str(num),fileformat)); 
  fileName = sprintf('C:\\result\\%02d',num);
  imwrite (I, 'fileName', 'jpg');
end

i tried this code in order to read and save images,although the reading part worked well,the saving part doesn't work,can any one plz help me? my images are: data (1),data (2),...

Answer 1

[Azzi Abdelmalek]

It's

imwrite (I, fileName, 'jpg');

or

imwrite (I, [fileName '.jpg']);

or

fileName = sprintf('C:\\result\\%02d.jpg',num);
imwrite (I, fileName);

[mohamad mohamad]

thank you very much indeed,it worked

Answer 2

[Image Analyst]

You don't need to include the 'jpg' argument to imwrite. And you could make this code more robust. Try it like this:

folder = 'c:/result'; % Forward slashes work just fine with Windows.
if exist(folder, 'dir')
  mkdir(folder);
end
% Loop over 4 images.
numberOfImages = 4;  % choose the number of images you want to give input
for num = 1 : numberOfImage
    % Read in input tif file.
    inputFileName = sprintf('data (%d).tif', num);
    fullInputFileName = fullfile(folder, inputFileName);
    if ~exist(inputFileName, 'file')
        continue; % Skip it not there.
    end
    I = imread(fullInputFileName); 

    % Write array to output file as a JPG format.
    outputFileName = sprintf('data (%d).jpg', num);
    % Could also have used outputFileName  = strrep(inputFileName, '.tif', 'jpg');
    fullOutputFileName = fullfile(folder, outputFileName);
    imwrite (I, fullOutputFileName);
end

For even more robustness, try putting the code into a try/catch where you can put up an error message when something happens, and maybe even try to fix it and continue on

try
  % Some code that might generate an error.
catch ME
  errorMessage = sprintf('Error in function %s() at line %d.\n\nError Message:\n%s', ...
    ME.stack(1).name, ME.stack(1).line, ME.message);
  fprintf(1, '%s\n', errorMessage);
  uiwait(warndlg(errorMessage));
end

In my job it's essential to write robust code. If I didn't, I probably would have been fired by now.

[mohamad mohamad]

thanks for your answer