How to Compress PDF Document in C#, VB.NET

//Loads the PDF document
PdfDocument doc = new PdfDocument("Test.pdf");
//Disables the incremental update
doc.FileInfo.IncrementalUpdate = false;
//Sets the compression level to best
doc.CompressionLevel = PdfCompressionLevel.Best;
//Saves and closes the resultant document
doc.SaveToFile("Compressed.pdf");
doc.Close();

'Loads the PDF document
Dim doc As New PdfDocument("Test.pdf")
'Disables the incremental update
doc.FileInfo.IncrementalUpdate = False
'Sets the compression level to best
doc.CompressionLevel = PdfCompressionLevel.Best
'Saves and closes the resultant document
doc.SaveToFile("Compressed.pdf")
doc.Close()

//Loads the PDF document
PdfDocument doc = new PdfDocument("Image.pdf");
//Disables the incremental update
doc.FileInfo.IncrementalUpdate = false;

//Traverses all pages
foreach (PdfPageBase page in doc.Pages)
{
    //Extracts images from page
    Image[] images = page.ExtractImages();
    if (images != null && images.Length > 0)
    {
        //Traverses all images
        for (int j = 0; j < images.Length; j++)
        {
            Image image = images[j];
            PdfBitmap bp = new PdfBitmap(image);
            //Reduces the quality of the image
            bp.Quality = 20;
            //Replaces the old image in the document with the compressed image
            page.ReplaceImage(j, bp);
        }
    }                
}
//Saves and closes the resultant document
doc.SaveToFile("Output.pdf");
doc.Close();

'Loads the PDF document
Dim doc As New PdfDocument("Image.pdf")
'Disables the incremental update
doc.FileInfo.IncrementalUpdate = False

'Traverses all pages
For Each page As PdfPageBase In doc.Pages
	'Extracts images from page
	Dim images As Image() = page.ExtractImages()
	If images IsNot Nothing AndAlso images.Length > 0 Then
		'Traverses all images
		For j As Integer = 0 To images.Length - 1
			Dim image As Image = images(j)
			Dim bp As New PdfBitmap(image)
			'Reduces the quality of the image
			bp.Quality = 20
			'Replaces the old image in the document with the compressed image
			page.ReplaceImage(j, bp)
		Next
	End If
Next
'Saves and closes the resultant document
doc.SaveToFile("Output.pdf")
doc.Close()