Public Class Form4
    Private ActivePic, NextPic As Bitmap
    Private i As Integer = 0
    Private PicSize As Size = New Size(560, 315)
 
    Private Sub Form4_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        ActivePic = GetPic("C:\...\XXX.JPG", PicSize)
        NextPic = GetPic("C:\...\YYY.jpg", PicSize)
        PB1.Image = New Bitmap(ActivePic)
        PB2.Image = New Bitmap(NextPic)
    End Sub
 
    Private Function GetPic(filename As String, picsize As Size) As Bitmap
        Dim bmpout As Bitmap
 
        Using bmp As New Bitmap(filename)
            Dim w, h, l, t As Integer
            w = CInt(bmp.Width * picsize.Height / bmp.Height) 
            h = picsize.Height
            If w > picsize.Width Then
                h = CInt(bmp.Height * picsize.Width / bmp.Width)
                w = picsize.Width
            End If 
            l = (picsize.Width - w) \ 2
            t = (picsize.Height - h) \ 2
 
            bmpout = New Bitmap(picsize.Width + 1, picsize.Height)
 
            Using gout As Graphics = Graphics.FromImage(bmpout)
                gout.InterpolationMode = _
                  Drawing2D.InterpolationMode.HighQualityBicubic
                gout.Clear(Color.Black)
 
                'gout.DrawImage(bmp, New Rectangle(l, t, w, h), _
                        New Rectangle(0, 0, bmp.Width, bmp.Height), _
                        GraphicsUnit.Pixel)
               'xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
                gout.DrawImage(bmp, New Rectangle(l - 1, t - 1, w + 1, h + 1), _
                        New Rectangle(0, 0, bmp.Width - 1, bmp.Height), _
                        GraphicsUnit.Pixel)
               'xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
            End Using
        End Using
 
        Return bmpout
    End Function
 
    Private Sub Btn_LR_Click(sender As Object, e As EventArgs) Handles _
      Btn_LR.Click
        i = 0
        Do While i <= 560 / 10
            Fade(0, 0, i * 10, 315, 0, 0, i * 10, 315)
        Loop
    End Sub
 
    Private Sub Btn_OU_Click(sender As Object, e As EventArgs) Handles _
      Btn_OU.Click
        i = 0
        Do While i <= 315 / 10
            Fade(0, 0, 560, i * 10, 0, 0, 560, i * 10)
        Loop
        Fade(0, 0, 560, 315, 0, 0, 560, 315)
    End Sub
 
    Private Sub Btn_L_Click(sender As Object, e As EventArgs) Handles _
      Btn_L.Click
        i = 0
        Do While i <= 560 / 10
            Fade(0, 0, i * 10, 315, 560 - i * 10, 0, i * 10, 315)
        Loop
    End Sub
 
    Private Sub Fade(A0, A1, A2, A3, A4, A5, A6, A7)
         i += 1
        'Threading.Thread.Sleep(100)
        Using bm As New Bitmap(PicSize.Width, PicSize.Height)
            Dim g2 As Graphics = Graphics.FromImage(bm)
            g2.DrawImage(ActivePic, 0, 0, PicSize.Width, PicSize.Height)
            g2.DrawImage(NextPic, New Rectangle(A0, A1, A2, A3), _
                                                   New Rectangle(A4, A5, A6, _
                                                   A7), GraphicsUnit.Pixel)
            Dim g As Graphics = PB1.CreateGraphics
            g.DrawImage(bm, 0, 0, PicSize.Width, PicSize.Height)
        End Using
    End Sub
End Class