Spliting and Merging

Hi,

I am trying to Split one multipage Pdf file into single pages and merge that splited pdfs' to a single PDF file using following methods.

Original file details: Size=3.50MB, Pages:80
Extract/split Obeservation: process time: 2 sec, size of all 80 files=5.02MB
Merge Obeservation: Process Time:1 Sec, Size =8.63MB

Private sub Extract()

Dim qp As New QuickPDFAX0718.PDFLibrary
                qp.UnlockKey(licenseKey)
                If qp.Unlocked = 1 Then
            Dim f As New OpenFileDialog
            f.Filter = "PDF Files|*.pdf"
            If f.ShowDialog = Windows.Forms.DialogResult.OK Then
             
                qp.LoadFromFile(f.FileName)
                           
                For i As Int32 = 1 To qp.PageCount

                    If qp.ExtractPages(i, 1) = 1 Then
                        qp.SaveToFile(Application.StartupPath & "\Extracted\Extract_Sample" & i.ToString & ".pdf")
                    End If
                    qp.LoadFromFile(f.FileName)
                Next
            End If
                      MsgBox("done")
        End If
end sub

Private sub Merge()

Dim qp As New QuickPDFAX0718.PDFLibrary
        qp.UnlockKey(licenseKey)
        If qp.Unlocked = 1 Then
            Dim d As New DirectoryInfo(Application.StartupPath & "\Extracted")
            Dim f() As FileInfo
            f = d.GetFiles()
            Dim outputfilename As String
            outputfilename = f(0).FullName
            For i As Int32 = 1 To f.Count - 1
                qp.MergeFiles(outputfilename, f(i).FullName, Application.StartupPath & "\Merge\test" & i & ".pdf")
                Application.DoEvents()
                outputfilename = Application.StartupPath & "\Merge\test" & i & ".pdf"
            Next
             MsgBox("Done")
        End If

end sub
Need assitance on:

1. Is it correct method for split/Merge?
2. If extracted pages total size is 5.02MB then why merged pdf file size increased?
3. How can I reproduce file after extracting to nearby its original size?


Pranav