使用GdPicture.NET圖形處理控件不僅能將圖像掃描成TIFF格式，并能將多頁的TIFF文件轉(zhuǎn)換為BMP格式文件，無疑給了圖像處理更多的選擇。

》》》下載GdPicture.NET最新試用版

示例代碼：

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim oGdPictureImaging As New GdPicture.GdPictureImaging
        oGdPictureImaging.SetLicenseNumber("XXXX") 'Replace XXXX by a valid or commercial KEY

        Dim InputImageID As Integer = oGdPictureImaging.CreateGdPictureImageFromFile("")
        Dim PageCount As Integer = 1

        If oGdPictureImaging.GetStat = GdPictureStatus.OK Then
            If oGdPictureImaging.TiffIsMultiPage(InputImageID) Then
                PageCount = oGdPictureImaging.TiffGetPageCount(InputImageID)
            End If

            For I As Integer = 1 To PageCount
                If I > 1 Then
                    oGdPictureImaging.TiffSelectPage(InputImageID, I)
                End If
                Dim TmpImageID As Integer = oGdPictureImaging.CreateClonedGdPictureImage(InputImageID)
                If oGdPictureImaging.GetStat = GdPictureStatus.OK Then
                    oGdPictureImaging.Resize(TmpImageID, 1728, 2286, Drawing2D.InterpolationMode.HighQualityBicubic)
                    oGdPictureImaging.SaveAsBMP(TmpImageID, "output" + Str(I) + ".bmp")
                    oGdPictureImaging.ReleaseGdPictureImage(TmpImageID)
                Else
                    MsgBox("Error on page " + Str(I) + ": " + oGdPictureImaging.GetStat.ToString)
                End If
            Next I

            oGdPictureImaging.ReleaseGdPictureImage(InputImageID)
            MsgBox("Done !")
        Else
            MsgBox("Can't open selected file !")
        End If
    End Sub