Hello Scott,

Unfortunatelly, the unsupported annotations are skipped during the import, so you cannot access their rectangles with Telerik's API. 

As for the units conversion calculations - I may give some hint that may help you achieve accurate calculations. RadPdfProcessing uses Device Independent Pixels (DIP) for its units and it positions the coordinate system by centering it at top left corner of the page with Y axis pointing down. Originally the PDF format uses Points for its units and it positions the coordinate system by centering it at bottom left corner of the page with Y axis pointing up. I am not sure about the library you have mentioned but most PDF libraries stick to the original PDF coordinate system and units. If this is the case, you should be able to convert the rectangles to RadPdfProcessing coordinate system by using code similar to the one below:

public static Rect ConvertRectToTopLeftDipCoordinateSystem(Rect rect, double radFixedPageHeight)
{
	double x = Unit.PointToDip(rect.X);
	// The rect.Height may not be necessary in these calculation in case when rect.Y is defining the top left corner point coordinate and not the bottom left corner point.
	double y = radFixedPageHeight -  Unit.PointToDip(rect.Y + rect.Height);
	double width = Unit.PointToDip(rect.Width);
	double height = Unit.PointToDip(rect.Height);
	
	return new Rect(x, y, width, height);
}

You may notice the comment in the method which states that the rect.Height may or may not be needed for Y calculations depending on rect.Y coordinate meaning.

I hope this is helpful. If you have other questions please open a support ticket as it is preferable for such discussions.

Regards,
Deyan

Hello Scott,

Thank you for the clarifications. We have now approved the feedback item. As you are following it, you will be notified when its status is changed from "Approved" to "In Development".

If you are interested only in visualizing the Redact annotation appearance (normal, mouse down and mouse over state), then you may also vote for and follow for this feedback item:
https://feedback.telerik.com/Project/143/Feedback/Details/210601-pdfviewer-implement-read-only-rendering-for-all-annotation-types

Meanwhile, you may take a look at the following forum post demo showing how to implement custom highlighting of some text in a PDF file and then save the higlights in a modified PDF using geometries. Although, this approach for marking some text is not using Redact annotations, there is some chance that it suits your needs in the concrete scenario. Here is the link to the forum post describing this demo in more details:
http://www.telerik.com/support/code-library/select-text-and-annotate-pdf#YJXa2UbmYEi6UOBR8vfOOA

If you have other questions or concerns you may open a new support ticket.

Regards,
Deyan

Hello Swetha,

Thank you for contributing to our feedback portal. We have just one clarifying question regarding the concrete annotation type. According to PDF format specification there is no annotation type called "Redaction". You may take a look at the available annotation types on page 615 in PdfReference 1.7:
http://www.adobe.com/content/dam/Adobe/en/devnet/acrobat/pdfs/pdf_reference_1-7.pdf

We have already logged some items in the feedback portal that may be related to your request. You may see the list of them as follows:
  - Form fields and form fillings, which are visualized by Widget annotations (checkbox, combobox, listbox, texbox and others). We have already implemented these annotations partially (read-only visualization) and it is likely that we implement full editing support for the next official release. You may follow the implementation progress by following this feedback item: 
https://feedback.telerik.com/Project/143/Feedback/Details/197877-pdfviewer-form-fields-and-forms-filling
  
  - FreeText annotation type implementation may be followed in this feedback item:  
https://feedback.telerik.com/Project/143/Feedback/Details/199351-pdfviewer-support-for-freetext-annotation-type
  
  - Popup annotation type implementation may be followed in this feedback item: 
https://feedback.telerik.com/Project/143/Feedback/Details/203379-pdfviewer-support-for-annotations-of-type-popup
  
  - If read-only support for all annotation types suits you needs you may also follow this feedback item: 
https://feedback.telerik.com/Project/143/Feedback/Details/210601-pdfviewer-implement-read-only-rendering-for-all-annotation-types
  
We are looking forward to contacting you in order to clarify whether the above-mentioned feedback items are related to your requirement or you need different annotation type.

Regards,
Deyan