Image Rotation without affecting Image

Question

Hi,

Am working in Image Processing application(Having picture box inside the User Control). In that i am doing Image Roatation based on the value entered in the text box. Image is rotating based on the given angle but 1 or 2 rotation original image got affected. I mean If the Image shape is Rectangle means it will become diagonal, round and so on.

Attached is the code.

Can anyone help me this to resolve.