C# .jpg help pls

Can i get some help?
I am making a program in c# that hides strings into images by changing each pixel color to be odd or even so i can store binary data in the pixels without changing the over all look of the image. Its just something i am making for fun but it only seems to work with .bmp's. I want to get it working with .jpg but i dont know how to do this. Right now i am just using System.Drawing.Bitmap to modify the images. Is their any other way that i can do this so it will be compatible with .jpg?

First off, the authorities don't know to analyze a normal looking picture for secret data, said Malkin. And second, with so many pictures on the Internet, the photos containing hidden messages can hide with the safety of numbers.
trollface.txt
Seriously, they don't think that the FBI or NSA or CIA have any way to detect that an image has been edited? Or that they don't have the computing power to scan images? Shit, some random company can come along and make an image search engine like tineye, I'm sure the three-letter agencies have the ability to make a steganography search.