Memory need on a bitmap stream

Question

Hello,

I have a question, what is the right/best way to free the memory. In my case, the method which I have wrote, is running in a thread and receives Bitmaps from the camera. These Bitmaps are shown in a pictuebox. So if the picturebox currently shows the bitmap it is not possible to dispose this bitmap and the reserved memory by the programm is growing all the time.

Any ideas?
(Visual Studio C# 2010 Express)