Handle documents with mismatched font Subtype and FontFile type when exporting PDF to image with SkiaImageFormatProvider.

Implement Viewer related properties in PdfProcessing in order to enable the users to set PrintScaling, Duplex, and other properties which are written in the Pdf Format specification as Interactive Features. 

ViewerPreferences are written a document's catalog. Check p.577 from pdf reference format specification, version 1.7

It would be great if the SkiaImageExportSettings offer a DocumentUnhandledException event allowing the developer to handle specific errors when exporting to image formats.

This would be an essential improvement in the existing Exception handling mechanism and would enable exporting PDF documents to images even though some parts of the image may not be completely supported: https://docs.telerik.com/devtools/document-processing/libraries/radpdfprocessing/features/handling-document-exceptions 

When exporting a PDF page to an image with the SkiaImageFormatProvider the following error occurs: 

System.IndexOutOfRangeException: 'Index was outside the bounds of the array.'

Missing spaces from TextFragments when exporting to plain text.

Error message: 

System.InvalidCastException: 'Unable to cast object of type 'Telerik.Windows.Documents.Fixed.FormatProviders.Pdf.Model.Elements.Forms.FormFieldsTree' to type 'Telerik.Windows.Documents.Fixed.FormatProviders.Pdf.Model.Types.PdfArray'.'

Specific TextFragments that are positioned a little further from the previous text are incorrectly recognized as word start by the text recognizer engine and result in additional white spaces in the exported text.  

Error message:

System.InvalidCastException: 'Unable to cast object of type 'Telerik.Windows.Documents.Fixed.FormatProviders.Pdf.Model.Types.PdfArray' to type 'Telerik.Windows.Documents.Fixed.FormatProviders.Pdf.Model.Elements.Functions.FunctionObject'.'

This error happens when importing a document.

Wrong clipping order when exporting a document with MarkedContent leads to a missing content.

The PDF/A-1 standard uses the PDF Reference 1.4 and specifies two levels of compliance:

- PDF/A-1b - Its goal is to ensure reliable reproduction of the visual appearance of the document.

- PDF/A-1a - Its objective is to ensure that documents content can be searched and re-purposed. This compliance level has some additional requirements:

• Document structure must be included.
• Tagged PDF.
• Unicode character maps
• Language specification.

Since the PdfProcessing and its PdfFormatProvider is compliant with the PDF Reference 1.7. , the produced documents are created with this version as well: 

InvalidCastException is thrown due to incorrectly parsed stream dictionary.

Import-export changes the color of the shading object.

Add support for "AcroSendMail:SendMail" named action.

Such a document can be considered as invalid. However, it would be good to provide functionality to handle it.  

Part 3 of the standard, published on October 15, 2012, differs from PDF/A-2 in only one regard: it allows embedding of arbitrary file formats (such as XML, CSV, CAD, word-processing documents, spreadsheet documents, and others) into PDF/A conforming documents.

Purpose: Long-term archiving of electronic documents with full semantic structure.

• "A" for Archiving

• Level "1a" ensures:

  • Tagged PDF (with proper logical structure and reading order)

  • Unicode text for proper text extraction and searchability

  • Embedded fonts (for consistent rendering)

• Restrictions:

  • No audio/video

  • No encryption

  • No JavaScript

  • No external content (everything must be self-contained)

• Based on: PDF 1.4 (Acrobat 5)

PdfProcessing: ArgumentException is thrown when importing a document with a duplicated filed names.

Wrong font loading when FontFile2 is CFF (Compact Font Format).