On windows based computers when you plug in your phone it should give you the option to enter the device as a hard drive and pull the pics off. I don't PW lock my phones so not sure if that affects it but I don't see why it would. Give it a shot.
If you have the computer that you backed up with before then you can do a backup again. That way you won't lose anything. A computer that did not backup the phone before would be stopped by the passcode.