MySQL：删除部分字符串，直到第三次到最后一次出现正斜杠

I've seen JavaScript parses for this, but not any suitable MySQL ... I have a column in my database that contains a string like this:

http://localhost/mysite/wp-content/uploads/2012/10/huge_eye-150x150.jpg

I need to be able to remove every part of that string except 2012/10/huge_eye-150x150.jpg

So I need to remove http://localhost/mysite/wp-content/uploads/ ... but keep in mind that not ALL of the rows will contain exactly http://localhost/mysite/wp-content/uploads/ ... some may contain a slightly different string because of a legacy system ... that's why I thought it might be most appropriate to find the third to last occurrence of /

Perhaps you have a better solution? Thank you!

Something like:

SUBSTRING_INDEX(url,'/',-3)