Comment récupérer la valeur d'un pixel d'une picturebox

Option Strict On
Public Class Form1
    Private Declare Function GetPixel Lib "gdi32" Alias "GetPixel" _
 (ByVal hdc As Int32, ByVal x As Int32, ByVal y As Int32) As Int32
    Dim pic As Image
    Dim x As New DataObject
    Private Sub Form1_Load(sender As System.Object, e As System.EventArgs) Handles MyBase.Load
        Dim ofd As New OpenFileDialog
        With ofd
            .Title = "Choisissez une image"
            .Filter = "jpeg (*.jpg)|*.jpg|gif (*.gif)|*.gif|tiff (*.tif)|*.tif|bmp (*.bmp)|*.bmp|png (*.png)|*.png"
            .FilterIndex = 1
            .RestoreDirectory = False
            If .ShowDialog() = Windows.Forms.DialogResult.OK Then
                pic = New Bitmap(.FileName)
                x.SetData(DataFormats.Bitmap, False, pic)
                System.Windows.Forms.Clipboard.SetDataObject(x)
            Else
                MessageBox.Show("Opération annulée par l'utilisateur!", "Ouverture image", MessageBoxButtons.OK, MessageBoxIcon.Information)
                Exit Sub
            End If
            .Dispose()
        End With
        Button1.Text = "Afficher image"
        Button2.Text = "Valeur pixel"
        Button3.Text = "Rétablir"
    End Sub
    Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click
        x = CType(System.Windows.Forms.Clipboard.GetDataObject, DataObject)
        pic = CType(x.GetData(DataFormats.Bitmap), Image)
        PictureBox1.Image = pic
        PictureBox1.SizeMode = PictureBoxSizeMode.Zoom
    End Sub
    Private Sub Button2_Click(sender As System.Object, e As System.EventArgs) Handles Button2.Click
        Me.BackgroundImage = PictureBox1.Image
        Me.BackgroundImageLayout = ImageLayout.Zoom
        PictureBox1.Visible = False
    End Sub
    Private Sub Button3_Click(sender As System.Object, e As System.EventArgs) Handles Button3.Click
        PictureBox1.Visible = True
        Me.BackgroundImage = Nothing
    End Sub
   Private Sub Form1_MouseDown(sender As Object, e As System.Windows.Forms.MouseEventArgs) Handles Me.MouseDown
        Dim pixelColor As Color
       Using gr As Graphics = Graphics.FromHwnd(Me.Handle)
            pixelColor = ColorTranslator.FromWin32(GetPixel(CInt(gr.GetHdc()), CInt(e.X), CInt(e.Y)))
        End Using
        Dim r As Byte = (pixelColor.R)
        Dim g As Byte = (pixelColor.G)
        Dim b As Byte = (pixelColor.B)
        Dim text As String = _
    String.Format("red: {0}, green: {1}, blue: {2}", New Object() {r, g, b})
        MsgBox(text) 'code RGB
    End Sub
  
End Class

  Private Sub PictureBox1_MouseDown(sender As Object, e As System.Windows.Forms.MouseEventArgs) Handles PictureBox1.MouseDown
        Dim TempBitmap As New Bitmap(PictureBox1.Image)
        Dim MyColor As Color
        MyColor = TempBitmap.GetPixel(e.X, e.Y)
        MessageBox.Show("Pixel x=" & e.X & ", y=" & e.Y & ", color=" & MyColor.ToString, "Color", MessageBoxButtons.OK, MessageBoxIcon.Information)
    End Sub

 Private Sub Button4_Click(sender As System.Object, e As System.EventArgs) Handles Button4.Click
        Dim TempBitmap As New Bitmap(PictureBox1.Image)
        Dim MyColor As Color
        Dim x As Integer = 100
        Dim y As Integer = 100
        MyColor = TempBitmap.GetPixel(x, y)
        'MessageBox.Show("Pixel x=" & e.X & ", y=" & e.Y & ", color=" & MyColor.ToString, "Color", MessageBoxButtons.OK, MessageBoxIcon.Information)
        ' Label1.Text = MyColor.ToString
        Dim aString As String = MyColor.ToString
        Dim rString As String
        rString = Mid(aString, 14)
        rString = Replace(rString, "]", "")
        MsgBox(rString)
        Dim bString As String
        bString = rString.Substring(9, 3) ' couleur Vert tu fais la suite pour les autres couleurs: 9 début de chaine 3 longueur de chaine à mettre dans une variable
        MsgBox(bString)
    End Sub

Option Strict On
Public Class Form1
    Private Declare Function GetPixel Lib "gdi32" Alias "GetPixel" _
 (ByVal hdc As Int32, ByVal x As Int32, ByVal y As Int32) As Int32
    Dim pic As Image
    Dim x As New DataObject
    Private Sub Form1_Load(sender As System.Object, e As System.EventArgs) Handles MyBase.Load
        Dim ofd As New OpenFileDialog
        With ofd
            .Title = "Choisissez une image"
            .Filter = "jpeg (*.jpg)|*.jpg|gif (*.gif)|*.gif|tiff (*.tif)|*.tif|bmp (*.bmp)|*.bmp|png (*.png)|*.png"
            .FilterIndex = 1
            .RestoreDirectory = False
            If .ShowDialog() = Windows.Forms.DialogResult.OK Then
                pic = New Bitmap(.FileName)
                x.SetData(DataFormats.Bitmap, False, pic)
                System.Windows.Forms.Clipboard.SetDataObject(x)
            Else
                MessageBox.Show("Opération annulée par l'utilisateur!", "Ouverture image", MessageBoxButtons.OK, MessageBoxIcon.Information)
                Exit Sub
            End If
            .Dispose()
        End With
        Button1.Text = "Afficher image"
        Button2.Text = "Valeur pixel"
        Button3.Text = "Rétablir"
    End Sub
    Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click
        x = CType(System.Windows.Forms.Clipboard.GetDataObject, DataObject)
        pic = CType(x.GetData(DataFormats.Bitmap), Image)
        PictureBox1.Image = pic
        PictureBox1.SizeMode = PictureBoxSizeMode.Zoom
        recupixel()
    End Sub
    Private Sub Button2_Click(sender As System.Object, e As System.EventArgs) Handles Button2.Click
        Me.BackgroundImage = PictureBox1.Image
        Me.BackgroundImageLayout = ImageLayout.Zoom
        PictureBox1.Visible = False
    End Sub
    Private Sub Button3_Click(sender As System.Object, e As System.EventArgs) Handles Button3.Click
        PictureBox1.Visible = True
        Me.BackgroundImage = Nothing
    End Sub
   Private Sub Form1_MouseDown(sender As Object, e As System.Windows.Forms.MouseEventArgs) Handles Me.MouseDown
        Dim pixelColor As Color
       Using gr As Graphics = Graphics.FromHwnd(Me.Handle)
            pixelColor = ColorTranslator.FromWin32(GetPixel(CInt(gr.GetHdc()), CInt(e.X), CInt(e.Y)))
        End Using
        Dim r As Byte = (pixelColor.R)
        Dim g As Byte = (pixelColor.G)
        Dim b As Byte = (pixelColor.B)
        Dim text As String = _
    String.Format("red: {0}, green: {1}, blue: {2}", New Object() {r, g, b})
        MsgBox(text) 'code RGB
    End Sub
  Private Sub PictureBox1_MouseDown(sender As Object, e As System.Windows.Forms.MouseEventArgs) Handles PictureBox1.MouseDown
        Dim TempBitmap As New Bitmap(PictureBox1.Image)
        Dim MyColor As Color
        MyColor = TempBitmap.GetPixel(e.X, e.Y)
        'MessageBox.Show("Pixel x=" & e.X & ", y=" & e.Y & ", color=" & MyColor.ToString, "Color", MessageBoxButtons.OK, MessageBoxIcon.Information)
        Label1.Text = MyColor.ToString
        Dim aString As String = MyColor.ToString
      Dim rString As String
        rString = Mid(aString, 14)
        ' rString = Replace(rString, ",", "  ")
        rString = Replace(rString, "]", "")
        MsgBox(rString)
        Dim bString As String
        bString = rString.Substring(9, 3) ' bString = "String"
        MsgBox(bString)
    End Sub
    Private Sub recupixel()
        Dim TempBitmap As New Bitmap(PictureBox1.Image)
        Dim MyColor As Color
        Dim x As Integer = 100
        Dim y As Integer = 100
        Dim vert As String
        Dim rouge As String
        Dim bleu As String
        MyColor = TempBitmap.GetPixel(x, y)
        'MessageBox.Show("Pixel x=" & e.X & ", y=" & e.Y & ", color=" & MyColor.ToString, "Color", MessageBoxButtons.OK, MessageBoxIcon.Information)
        Dim aString As String = MyColor.ToString
        Dim rString As String
        rString = Mid(aString, 14)
        rString = Replace(rString, "]", "")
        rString = Replace(rString, ",", " ")
        MsgBox(rString)
        rouge = rString.Substring(3, 3) ' couleur rouge
        MsgBox(rouge)
        vert = rString.Substring(9, 3) ' couleur Vert 
        MsgBox(vert)
        bleu = rString.Substring(16, 3) ' couleur bleu 
        MsgBox(bleu)
    End Sub
End Class

http://fr.openclassrooms.com/informatique/cours/apprenez-a-programmer-en-vb-net/historique-et-visual-basic-express-2010

Private Sub recupixel()
        Dim TempBitmap As New Bitmap(PictureBox1.Image)
        Dim MyColor As Color
        Dim x As Integer = 100
        Dim y As Integer = 100
        MyColor = TempBitmap.GetPixel(x, y)
        'MessageBox.Show("Pixel x=" & e.X & ", y=" & e.Y & ", color=" & MyColor.ToString, "Color", MessageBoxButtons.OK, MessageBoxIcon.Information)
        Dim aString As String = MyColor.ToString
        Dim rString As String
        rString = Mid(aString, 14)
        rString = Replace(rString, "]", " ")
        MsgBox(rString)
        Dim s As String = rString
        Dim separateur As Char = CChar(",")
        Dim nom() As String
        nom = s.Split(separateur)
        nom(0) = Replace(nom(0), "R=", "")
        rouge = nom(0)
        MsgBox(rouge)
        nom(1) = Replace(nom(1), "G=", "")
        vert = nom(1)
        MsgBox(vert)
        nom(2) = Replace(nom(2), "B=", "")
        bleu = nom(2)
        MsgBox(bleu)
    End Sub

  Dim vert As String
    Dim rouge As String
    Dim bleu As String