Revision history [back]

I want to correct that after colon is not user name but group name:

sudo chown -R user_name:group_name opencv2

Yes some distributions make group name clones from usernames but this is kind of feature you should not always expect. I also want to point out that changing user is not always good idea (as someone already pointed out). In such cases I would suggest relaxing group permissions:

sudo find PATH_NAME -type f -exec chmod g+rw {} \;
sudo find PATH_NAME -type d -exec chmod g+rwx {} \;

Then you can add any user requiring access to those files into /etc/groups and meanwhile don't break anything what already works.