how to merge images in c#?????????

Tip: Define image, your question is ambiguous.

Do you mean by "merging" that you want to combine the two images into one image? If yes, what is the result that you expect from the "merging"?
Do you want the resulting image to be a combination of the two source images? For example, if the first image has a car in it and the second image has a plane in it. Will the resulting image have both a car and a plane visible with some sort of transparency? Or will the resulting image have only one of the objects where both images overlap?
In both cases the technique is similar but for the first option you will need to account for alpha and transparency. I found the following link that I think might be helpful:
http://support.leadtools.com/CS/forums/16759/ShowPost.aspx#42100

Be a part of the DaniWeb community

We're a friendly, industry-focused community of developers, IT pros, digital marketers, and technology enthusiasts meeting, networking, learning, and sharing knowledge.