C# .NET - How Extract image based on Given Coordinates.?

I want to extract data from PDF file based on given coordinates(llx,llx,urx,ury). here i have extracted the data by coordinates.its fine, but here the problem is, i want to extract image also by coordinates. (here image means, in editable pdf form i have check box, when user checked on that it will be checked. after convert to that editable pdf to non-editable pdf, it displays checked image. )  here i can't get the checked image data.
if it is either image or 1 or 0 or true or false anything else, here i need to get the checkbox value or image or 0 or 1 or true o false.

Here i used itextsharp to extract data from pdf by coordinates.

 if anyone know about this could you share your knowledge.

You are going to need a third party PDF reading component.  The image is an object on the document.  These components will let you write code that can find the object and extract it.  Aspose PDF is a good one.  I think Syncfusion still has one too.