GdPicture Imaging Forums

Code: Select all

        Const CONVERT_1BPP As Boolean = False 'Set true to convert all bitmap to black & white
        Const SCALE_FACTOR As Single = 2.0 'Set 1 for no scale.
        Const JPEG_QUALITY_COLOUR As Integer = 60 'between 1 and 100
        Const JPEG_QUALITY_GRAY As Integer = 30 'between 1 and 100
        Const SOURCE_PATH As String = "c:\test.pdf"
        Const DEST_PATH As String = "c:\result.pdf"

        Using gdPicturePDF As New GdPicturePDF
            Dim oGdPictureImaging As New GdPictureImaging

            If gdPicturePDF.LoadFromFile(SOURCE_PATH, False) = GdPictureStatus.OK Then
                If gdPicturePDF.IsEncrypted() Then
                    If Not gdPicturePDF.SetPassword("") Then
                        MsgBox("password protected document")
                        Return
                    End If
                End If
                gdPicturePDF.SetCompressionForBitonalImage(PdfCompression.PdfCompressionJBIG2)
                gdPicturePDF.SetCompressionForColorImage(PdfCompression.PdfCompressionJPEG)
                For i As Integer = 1 To gdPicturePDF.GetPageCount()
                    gdPicturePDF.SelectPage(i)
                    Dim imageCount As Integer = gdPicturePDF.GetPageImageCount
                    If imageCount > 0 Then
                        For j As Integer = 0 To imageCount - 1
                            Dim ImageID As Integer = gdPicturePDF.ExtractPageImage(j + 1) 'Warning: 1-based
                            If ImageID <> 0 Then
                                If CONVERT_1BPP Then
                                    oGdPictureImaging.ConvertTo1Bpp(ImageID)
                                End If
                                Dim bitDepth As Integer = oGdPictureImaging.GetBitDepth(ImageID)
                                If bitDepth > 8 Then
                                    gdPicturePDF.SetJpegQuality(JPEG_QUALITY_COLOUR)
                                Else
                                    If bitDepth = 8 Then
                                        If oGdPictureImaging.IsGrayscale(ImageID) Then
                                            gdPicturePDF.SetJpegQuality(JPEG_QUALITY_GRAY)
                                        Else
                                            gdPicturePDF.SetJpegQuality(JPEG_QUALITY_COLOUR)
                                        End If
                                    End If
                                End If
                                Dim imageResName As String = gdPicturePDF.GetPageImageResName(j)

                                If SCALE_FACTOR <> 1.0F Then
                                    oGdPictureImaging.Scale(ImageID, 100 / SCALE_FACTOR, Drawing2D.InterpolationMode.HighQualityBicubic)
                                End If

                                gdPicturePDF.ReplaceImage(imageResName, ImageID, False, True)

                                Dim newImageResName As String = gdPicturePDF.AddImageFromGdPictureImage(ImageID, False, False)
                                oGdPictureImaging.ReleaseGdPictureImage(ImageID)
                            End If
                        Next
                    End If
                Next
                If gdPicturePDF.SaveToFile(DEST_PATH, True) = GdPictureStatus.OK Then
                    MsgBox("done")
                Else
                    MsgBox("error saving file file: " + DEST_PATH + ". Status: " + gdPicturePDF.GetStat.ToString)
                End If
                gdPicturePDF.CloseDocument()
            Else
                MsgBox("Can't open file: " + SOURCE_PATH + ". Status: " + gdPicturePDF.GetStat.ToString)
            End If
        End Using

Code: Select all

gdPicturePDF.ReplaceImage(imageResName, ImageID, False, True)

Code: Select all

Public Shared Function CompressToNewPDFWith1Bpp(imageBytes As Byte()) As Byte()
        Dim rBytes As Byte() = Nothing

        Dim oPDF As New GdPicturePDF
        oPDF.EnableCompression(Compress:=True)
        oPDF.NewPDF(PDFA:=False)

        Using ms As New IO.MemoryStream(imageBytes)
            Dim workingPDF As New GdPicturePDF
            If workingPDF.LoadFromStream(ms) = GdPictureStatus.OK Then
                For i As Int32 = 0 To workingPDF.GetPageCount - 1
                    workingPDF.SelectPage(i + 1)

                    Dim oPImaging As New GdPictureImaging
                    Dim imageID = workingPDF.RenderPageToGdPictureImageEx(100, RenderFormFields:=False)
                    oPImaging.ConvertTo1Bpp(imageID)

                    oPDF.AddImageFromGdPictureImage(imageID, ImageMask:=False, DrawImage:=True)
                Next

                workingPDF.CloseDocument()
            End If
        End Using

        Using rStream As New IO.MemoryStream
            oPDF.SaveToStream(rStream, PackDocument:=True)

            rBytes = rStream.ToArray
        End Using

        oPDF.CloseDocument()

        Return rBytes
    End Function