Error => Unable to open file "Image1" for writing. You might not have write permission.

Am getting an error "Unable to open file "Image1" for writing. You might not have write permission." while running this program. Please help me

    x=videoinput('winvideo',1);
for i=1:10
    preview(x);
    pause(1);
    img=getsnapshot(x);
    fname=['Image' num2str(i)];
    imwrite(img,fname,'jpg');
    pause(0.1);
 end

[Mridul Pandey]

change present working directory to the desired directory where you want to save the file either change in on the command window or script. like.. cd c:\folder\folder\... and then use imsave(...) function.

Answer 1

[Adam]

Surely the error is self-explanatory? How exactly are you expecting us to give you write access to your folder? Can you open other files from that folder? Can you create new files in it outside of Matlab?

[Jan]

For the last sentence:

folder = tempdir;  % Adjust to your needs
fname = fullfile(folder, ['Image' num2str(i)]);

[Maria Hernandez]

It does not work

[Walter Roberson]

img = randi([0 255], 320, 240, 3, 'uint8');
imshow(img)

i = 7;
folder = tempdir;  % Adjust to your needs
fname = fullfile(folder, ['Image' num2str(i)]);
imwrite(img,fname,'jpg');
dir(folder)

.                                        GDS-CACHE                                hsperfdata_wguser                        worker.properties                        
..                                       Image7                                   jetty-0.0.0.0-8080-worker-webapp-_-any-  ws_override.properties                   
Editor_dswgc                             hsperfdata_mcguser                       matlabpref                               

Image7 is present in the output directory. Looks to me as if it worked.

Note: most of the time you want to append a file extension to the file name, such as

fname = fullfile(folder, ['Image' num2str(i) '.jpg']);

Answer 2

[Milad Kassaie]

This is a common issue in MS Windows. Write access is restricted in system folders, including where MATLAB is typically installed.

The soultion is to close MATLAB. Then right-click on the MATLAB icon and choose "Run as Administrator". Matlab will now have write access everywhere.

I hope this helps.

[Walter Roberson]

Run As Adminstrator is not recommended; the operating system restrictions are there to prevent malware from infecting the system, and to reduce accidental user corruption of files.

You should instead take care to write to a directory you have write access to.

See for example the use of tempdir() that Jan and I suggested, https://www.mathworks.com/matlabcentral/answers/330185-error-unable-to-open-file-image1-for-writing-you-might-not-have-write-permission#comment_437586