Generally, transformation methods which can be used for displaying data mainly depend on the form control of a certain field.
So, for standard TextBox fields, you can usually take advantage of a simple
<%# Eval("FineText")%> but images are often more complex because there are several form controls which can store them and almost each one of them does it in a different way. For example, here are methods which work with particular controls:
Image selection - <img src="<%# GetDocumentUrl("FineImage", "") %>" />
Media selector - <img src="<%# GetAbsoluteUrl(Eval("FineImage").ToString()) %>" width="900px" />
File field - <%# GetImage("FileField", 300) %></td>
As you can see, the logic might be quite tricky so it would be best if you could specify which form control you use so we could narrow the list of appropriate methods down.