I tried to use this way:
QuoteAlternative 3 (workaround):
You may download one of many free programs that resize images. Then resize the images to a smaller resolution (like 800 x 600) by the batch into a different folder while maintaining the same filenames.
Upload the resized images to Coppermine. Then use your FTP client to overwrite the images with the higher resolution images.
But! Coppermine gallery has set CHMOD 644 on all of this files and I cannot change it. My ftp client says, that the problem is in the file descriptor. However I can't upload new and overwrite existing images in the folder. What should I do?
CHMOD (if you can) using your FTP app to 777 or 755. If this doesn't work, you'll have to change ownership (CHOWN). Maybe you're not allowed to do this - in this case, ask your webhost to CHOWN for you.
When I try to CHMOD any picture, FTP client says, that it has a bad file descriptor, and CHMOD is set back to 644.
Contact your host and ask them to change ownership for you.
Nevertheless it(CHOWN) has no effect. :-[
Maybe more detailed explanation will reveal something... When I try to replace an existing file with another one, my client says:
QuoteRemote file exist check: 'vvardenfell_map.jpg'.
SIZE vvardenfell_map.jpg
213 439898
MDTM vvardenfell_map.jpg
213 20051110192315
PASV
227 Entering Passive Mode (66,36,255,40,128,148)
Opening data connection to 66.36.255.40 Port: 32916
STOR vvardenfell_map.jpg
553 Rename/move failure: Permission denied
PASV
227 Entering Passive Mode (66,36,255,40,53,203)
Opening data connection to 66.36.255.40 Port: 13771
MLSD
150 Accepted data connection
226-ASCII
226-Options: -a -l
226 106 matches total
12531 bytes transferred. (21,1 КБ/s) (578 ms)
Transfer failed.
The problem is here: 553 Rename/move failure: Permission denied
But! If I try to change CHMOD, it says:
QuoteSITE CHMOD 777 vvardenfell_map.jpg
550 Could not change perms on vvardenfell_map.jpg: Bad file descriptor