I have a relatively large (merged) PDF document with fonts that are partially embedded and want to reduce the size of the document by first unembedding fonts and removing duplicates, then fully embedding the fonts used.
I use the following two-step approach:
input.OptimizeResources(new Document.OptimizationOptions()
{
LinkDuplcateStreams = true,
UnembedFonts = true
});
foreach (Page page in input.Pages)
{
Console.Out.WriteLine("page " + page.Number);
var fonts = page.Resources.Fonts;
if (fonts != null)
{
foreach (Font font in fonts)
{
font.IsSubset = false;
font.IsEmbedded = true;
}
}
}
This works on some input PDF files, but on others it fails with a NullReferenceException:
System.NullReferenceException was unhandled
HResult=-2147467261
Message=Object reference not set to an instance of an object.
Source=Aspose.Pdf
StackTrace:
at . ( , , Int32 )
at . ( , , Int32 )
at . ( , , Int32 )
at . ( , , Int32 )
at . ( , , Int32 )
at . ( , , Int32 )
at . ( , , Int32 )
at . ( , , Int32 )
at . ( , , Int32 )
at . ( , , Int32 )
at . ( , , Int32 )
at . ( , , Int32 )
at . ( , , Int32 )
at . ( , , Int32 )
at . ( , , Int32 )
at . ( , , Int32 )
at Aspose.Pdf.Document. . ( )
at Aspose.Pdf.Document. . ( )
at Aspose.Pdf.Document. . ( )
at Aspose.Pdf.Document. . ( )
at Aspose.Pdf.Document. . ( )
at Aspose.Pdf.Document. . ( )
at Aspose.Pdf.Document. . ( )
at Aspose.Pdf.Document. . ( )
at Aspose.Pdf.Document. . ( )
at Aspose.Pdf.Document. (OptimizationOptions )
at Aspose.Pdf.Document.OptimizeResources(OptimizationOptions strategy)
The version of Aspose.Pdf is 16.11.0.0.
If I change LinkDuplcateStreams to false, then the process runs through, but the fonts are embedded once per page, so the output file gets very big.
Am I doing something wrong? Is there a different way to achieve my goal?