First of all why do you want to create an image and then button on it.
You can simply achieve this with a button.
First, create a Button and add any text as you wish.
then,to include the image, go to BackgroundImage of the Buttonproperty and add an image. This will lead you to what you require. This way your text will appear on your background.
Look at this code,
btnLogin.Text = "This will appear";
btnLogin.BackgroundImage = ((System.Drawing.Image)(Properties.Resources.PTLY_logo));
Let me know if you have any questions regarding this issue. Thanks.