Problem of imwrite permission

Hi!, recently I have been troubled with getting cropped picture for given input. What I expected are from input PolyU_0034_F.bmp will become crop_0034_F.jpg for example the code are:

file = dir('C:\Program Files\MATLAB\R2017a\bin\FYP\PolyU\*.bmp');
input = {file.name}';
c = input;
for i = 1:length(file)

    fname = strcat('C:\Program Files\MATLAB\R2017a\bin\FYP\PolyU\',file(i).name);

     a = imread(fname);

     b = imcrop(a,[140,65,150,150]);

     c{i} = strrep(fname, 'PolyU', 'crop');

     d = c{i};

     imwrite(b,strrep(d, '.bmp', '.jpg'));

     imshow(b);
end

However, The error given out are

   Error using imwrite (line 454)
Unable to open file "C:\Program Files\MATLAB\R2017a\bin\FYP\crop\crop_037_F_10.jpg" for writing.  You might not have write
permission.
Error in corp1 (line 24)
    imwrite(b,strrep(d, '.bmp', '.jpg'));

This is weird for 2 reasons. First, the file direction on error is different folder (crop) even though I use folder of (PolyU). Second, This code was done on different folder(FYP) and execute very well. Are same code in different folder need to readjust so that it could work again?

Thanks for your time!

[Walter Roberson]

"First, the file direction on error is different folder (crop) even though I use folder of (PolyU)."

No you do not. You strrep(fname, 'PolyU, 'crop') to replace PolyU with crop, and then you use that as the destination for imwrite, so it is expected that you write to the crop directory.

[Muhammad Bariq Azmi]

Yeah, I don't realized about the path before also changed. Thanks for help!!!

Answer 1

[Steven Lord]

In general trying to write files in a directory under the MATLAB root directory is probably not a good idea, and in this case the error indicates you don't have write permissions to that directory and/or that file.

I strongly recommend moving your FYP subdirectory somewhere else that is NOT under "C:\Program Files\MATLAB\R2017a".

[Stephen23]

Or indeed do not use anywhere under C:\Program Files at all. The best location to use for storing files is your user directory.

[Muhammad Bariq Azmi]

Sorry sir, I still have error of write permission. This time, the error point to C:\FYP\work\FYP\crop\crop_037_F_10.jpg. The folder that i keep input picture are also different from error (C:\FYP\work\FYP\PolyU)

[Walter Roberson]

See https://technet.microsoft.com/en-us/library/2009.07.geekofalltrades.aspx