Picturebox et Drag'n drop

bonjour
ca implique de comparer les 2 images pixel par pixel.GDI+ le permet mais ca peut prendre des heures de calcul (fonction getpixel).
L'autre methode infaillible c'est d'utiliser le hashcode d'une donnee calcule par un algo de cryptage (System.Security.Cryptography) qui calcule un hascode pour chacune des donnees à comparer.
Voici le dragdrop d'un picturebox et une classe ComparingImages dedie au calcul du hashcode du picturebox1.image "source" et du picturebox2.image "cible".

Code:

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Public Class Form2
    Dim bmp1 As Bitmap
    Dim bmp2 As Bitmap
    Private Sub Form2_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
        Me.AllowDrop = True
 
        bmp2 = My.Resources.Nénuphars
        bmp1 = My.Resources.Collines
        PictureBox1.Image = bmp1
        PictureBox2.Image = bmp2
 
    End Sub
    Private Sub Form2_MouseDown(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles Me.MouseDown
        Me.PictureBox1.DoDragDrop(PictureBox1.Image, DragDropEffects.Copy Or DragDropEffects.Move)
 
    End Sub
 
 
    Private Sub Form2_DragEnter(ByVal sender As Object, ByVal e As System.Windows.Forms.DragEventArgs) Handles Me.DragEnter
        If (e.Data.GetDataPresent(DataFormats.Bitmap)) Then
            e.Effect = DragDropEffects.Copy
        Else
            e.Effect = DragDropEffects.None
        End If
    End Sub
    Private Sub Form2_DragDrop(ByVal sender As Object, ByVal e As System.Windows.Forms.DragEventArgs) Handles Me.DragDrop
        Dim x As Integer = Me.PointToClient(New Point(e.X, e.Y)).X
        Dim y As Integer = Me.PointToClient(New Point(e.X, e.Y)).Y
        If (x >= PictureBox2.Location.X And x <= PictureBox2.Location.X + PictureBox2.Width _
        And y >= PictureBox2.Location.Y And y <= PictureBox2.Location.Y + PictureBox2.Height) Then
            'Dim files() As String = CType(e.Data.GetData(DataFormats.FileDrop), String())
            'PictureBox1.Image = Image.FromFile(files(0))
            Dim nn As Bitmap = e.Data.GetData(DataFormats.Bitmap)
            If ComparingImages.Compare(PictureBox2.Image, e.Data.GetData(DataFormats.Bitmap)) Then
                PictureBox2.Image = e.Data.GetData(DataFormats.Bitmap)
            End If
        End If
 
    End Sub
 
End Class
'classe à mettre dans un fichier classe à part dans le meme projet
'si les 2 images n'ont pas la meme taille inutile d'aller plus loin
'sinon on calcule le hashcode et comparison
Imports System
Imports System.Drawing
Imports System.Drawing.Imaging
Imports System.Security.Cryptography
 
Public Class ComparingImages
    Public Enum CompareResult
        ciCompareOk
        ciPixelMismatch
        ciSizeMismatch
    End Enum
    Public Shared Function Compare(ByVal bmp1 As Bitmap, ByVal bmp2 As Bitmap) As CompareResult
        Dim cr As CompareResult = CompareResult.ciCompareOk
        'Test pour voir si meme taille  image
        If (bmp1.Size <> bmp2.Size) Then
            cr = CompareResult.ciSizeMismatch
        Else
            'Convertir chaque image en  byte array
            Dim ic As System.Drawing.ImageConverter = New System.Drawing.ImageConverter()
            Dim btImage1() As Byte = New Byte(1) {}
            btImage1 = CType(ic.ConvertTo(bmp1, btImage1.GetType()), Byte())
            Dim btImage2() As Byte = New Byte(1) {}
            btImage2 = CType(ic.ConvertTo(bmp2, btImage2.GetType()), Byte())
            'Cacule  hash pour chaque image
            Dim shaM As SHA256Managed = New SHA256Managed()
            Dim hash1() As Byte = shaM.ComputeHash(btImage1)
            Dim hash2() As Byte = shaM.ComputeHash(btImage2)
            'Compare les valeurs hash 
            For i As Integer = 0 To (i < hash1.Length And i < hash2.Length And _
                              (cr = CompareResult.ciCompareOk))
                If hash1(i) <> hash2(i) Then
                    cr = CompareResult.ciPixelMismatch
                End If
            Next
        End If
        Return cr
    End Function
 
End Class

bon code.....