Is possible to use image manipulation class without 777 permissions?

[eluser]fran-quero[/eluser]
Hello. I´ve done a little application using image manipulation class, and I have read in documentation:
http://ellislab.com/codeigniter/user-gui...e_lib.html

Note: In order for the image class to be allowed to do any processing, the image file must have "write" file permissions. For example, 777.

I wonder if my application will work in a shared hosting like Hostgator, where 777 are not allowed.

Is there an alternative way to do this class work without 777 permissions?

Thanks in advance for your answers.