RadPdfViewer partially supports CCITTFaxDecode (that is basically TIFF). There are some limitations that are not supported at this stage like EncodedByteAlign = true or Group 3, 2-D encoding.

When a pdf/a compliant document is opened in Adobe, there is a bar saying that the document is compliant with the standard. Expose such functionality in PdfViewer as well.

The current implementation relies on valid cross-reference table offsets in the PDF documents so that PDF objects are easily found and parsed. However, a mechanism for importing documents with invalid cross-reference table offsets may be implemented.

The attached project shows how to repair such documents.

When importing a document with empty pages collection an ArgumentNullException: 'Value cannot be null.
Parameter name: page', is thrown, which leads to application crash.

An implementation of JPXDecoder should be created to allow the decompression of data encoded using the wavelet-based JPEG2000 standard.

I am using the PDFViewer control in a VisualStudio VB.NET application. The PDF is not showing all the details as it appears in Adobe PDF Reader. In particular, the text is not showing up (but is highlighted when selected) and there is gray shading that is not visible. See attached sample file. Please advise.

The offset of the CropBox is not respected and is always treated as 0.

Workaround: Import the document with PdfProcessing, change the CropBox offsets of the pages to 0, export the modified document and then import it in PdfViewer.

The EI keyword defines an operator for ending the image data. When the stream contains the same sequence, the parser treats that as an end of the image data. As a result, the image and the following content cannot be properly parsed and there is missing content when the document is visualized.

A remote go-to action is similar to an ordinary go-to action but jumps to a destination in another PDF file instead of the current file.

To reproduce:

Open a large document and start scrolling fast. 

The pages a blank when scrolling and are rendered after scrolling stops.

When the Interactive Form Fields are in read-only mode, the user should not be able to change the value of the field. The associated Form Field widgets should not interact with the user, e.g. they should not respond to mouse clicks or change their appearance in response to mouse motions.

When a PDF document contains images compressed with CCITTFaxDecode with applied BlackIs1 parameter, black color is visualized as white and white as black.

Please refer to the attached sample screenshot demonstrating how the document look in Adobe and in RadPdfViewer.

Currently, RadPdfViewer uses WPF DrawingContext class for drawing page elements to a Canvas.  When PDF page has many content elements (usually geometries) drawing the page may be time-consuming and freezes the UI. 

Instead, we should consider implementing another approach for rendering the content asynchronously which would improve the user experience. 

Some files when opened with PdfViewer will throw a KeyNotFoundException which will be handled. Parts of the text in the file might or might not be missing.

When the file has an annotation with a destination and this destination is missing from the destinations (Dests) collection of the catalogue, KeyNotFoundException is thrown when you try to scroll to the page where the annotation is located. A better behavior would be for nothing to happen when trying to click on the annotation leading to the destination.

structure
The hierarchical document structure is a means to describe the PDF document structure, which is currently not supported. See 10.6.1 Structure Hierarchy on 856 page of the PDF specification for details.
This document structure is an alternative to the standard PDF structure and most non-Adobe software does not support it.

The document might have been created with Adobe software like Adobe LiveCycle Designer. Very often the document contains some fallback text in the standard PDF structure like:
"Please wait... If this message is not eventually replaced by the proper contents of the document, your PDF viewer may not be able to display this type of document."
"The document you are trying to load requires Adobe Reader 8 or higher. You may not have the Adobe Reader installed or your viewing environment may not be properly configured to use Adobe Reader. For information on how to install Adobe Reader and configure your viewing environment please see  http://www.adobe.com/go/pdf_forms_configure."
"For the best experience, open this PDF portfolio in Acrobat X, Reader X, or later."

When there is no ToUnicode CMap, the text from the Simple Font instance (TrueType or Type1 font) should be extracted by mapping the glyph name to its corresponding charcode according to Adobe Glyph List. Additionally, the Differences array should be included in these calculations when there is custom encoding. The current implementation of RadPdfViewer makes ToString to the original char id byte value which leads to wrong characters. 

More information about this may be seen in the second point of section "5.9.1Mapping Character Codes to Unicode Values" on page 470 in PdfReference 1.7.