如何在视图2中的php代码块中读取过滤器变量？

I'm trying to create an img link manually with php in the header field of a view, in drupal 6. I need to read the value of one of the filters, but can't find the right variable to read. I thought I could print_r($view->filters) but it didn't give me anything, and I eventually found out that isset($view) is false.I'm trying to create an img link manually with