Getting different color values with getpixel and lockbits

Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click
        ComparePixelReads()
    End Sub

    ''' <summary>
    ''' Compares the pixel reads.
    ''' </summary>
    Public Sub ComparePixelReads()
        Try


            Using sw As New System.IO.StreamWriter("D:\pixeltest\pixeloutput.txt", False)

                Dim tmp As System.Drawing.Bitmap = System.Drawing.Bitmap.FromFile("D:\pixeltest\ManagerPanel.bmp")
                Dim jImg As System.Drawing.Bitmap = ConvertToRGB(tmp)


                Dim jc2(jImg.Height, jImg.Width) As System.Drawing.Color
                Dim jc3(jImg.Height, jImg.Width) As System.Drawing.Color


                '//get pixel usage (very slow)
                For i As Integer = 0 To jImg.Height - 1
                    For j As Integer = 0 To jImg.Width - 1
                        Dim cl As System.Drawing.Color = jImg.GetPixel(j, i)
                        jc2(i, j) = cl
                    Next
                Next

                '//lock bits method (much faster)
                Dim bd As System.Drawing.Imaging.BitmapData = jImg.LockBits(New System.Drawing.Rectangle(0, 0, jImg.Width, jImg.Height), System.Drawing.Imaging.ImageLockMode.ReadOnly, System.Drawing.Imaging.PixelFormat.Format32bppArgb)

                Dim sourceBuffer((bd.Stride * bd.Height)) As Byte
                '//copy intPtr to buffer
                System.Runtime.InteropServices.Marshal.Copy(bd.Scan0, sourceBuffer, 0, sourceBuffer.Length)

                '//unlock bits
                jImg.UnlockBits(bd)


                Dim st As Integer = 0
                Dim bb, bg, br, ba As Integer

                For i As Integer = 0 To jImg.Height - 1 '// 'added -1 so don't end up with index out of range

                    st = bd.Stride * i '//'get index for current row

                    For j As Integer = 0 To jImg.Width - 1 '// 'added -1 so don't end up with index out of range

                        '//'Changed order to BGRA order
                        bb = sourceBuffer(st)
                        bg = sourceBuffer(st + 1)
                        br = sourceBuffer(st + 2)
                        ba = sourceBuffer(st + 3)

                        jc3(i, j) = System.Drawing.Color.FromArgb(ba, br, bg, bb) '//'not sure if you can do this... thinking it should be Color.FromARGB(a, r, g, b)

                        st += 4 '//'increment for the 4 bytes we read

                    Next

                Next

                Dim outputCompare1 As New System.Drawing.Bitmap(jImg.Width, jImg.Height, System.Drawing.Imaging.PixelFormat.Format32bppArgb)
                Dim outputCompare2 As New System.Drawing.Bitmap(jImg.Width, jImg.Height, System.Drawing.Imaging.PixelFormat.Format32bppArgb)

                If (jc2.Length = jc3.Length) Then

                  For y As Integer = 0 To jImg.Height - 1

                        For x As Integer = 0 To jImg.Width - 1
                            'write new pixels from jc2
                            outputCompare1.SetPixel(x, y, jc2(y, x))
                            'write new pixels from jc3
                            outputCompare2.SetPixel(x, y, jc3(y, x))

                            sw.WriteLine(String.Format("PixelGet: {0}      LockBitsGet: {1}", "(" & y.ToString() & ", " & x.ToString() + ")" & jc2(y, x).ToArgb().ToString(), "(" & y.ToString() & ", " & x.ToString() & ")" & jc3(y, x).ToArgb().ToString()))

                        Next

                    Next

                End If

                outputCompare1.Save("D:\pixeltest\jc2.bmp")
                outputCompare2.Save("D:\pixeltest\jc3.bmp")

            End Using

        Catch ex As Exception
            MessageBox.Show(ex.Message & vbCrLf & ex.StackTrace)
        End Try
    End Sub



    ''' <summary>
    ''' Converts to Format32bppArgb.
    ''' </summary>
    ''' <param name="original">The original.</param>
    ''' <returns></returns>
    Public Function ConvertToRGB(ByVal original As Bitmap) As Bitmap

        If original.PixelFormat = Imaging.PixelFormat.Format32bppArgb Then Return original

        Dim newImage As Bitmap = New Bitmap(original.Width, original.Height, System.Drawing.Imaging.PixelFormat.Format32bppArgb)
        newImage.SetResolution(original.HorizontalResolution, original.VerticalResolution)

        Dim g As Graphics = Graphics.FromImage(newImage)
        g.DrawImageUnscaled(original, 0, 0)
        g.Dispose()

        Return newImage
    End Function