how to rotate a picture(image) in VB.NET

you can use matrices wich found in :
Drawing2D.Matrix
I wrote this example for you it can help:
create new form and add a button named as button1 then write the folowing

Public Class Form1
    Dim gr As Graphics
    Dim mat As New Drawing2D.Matrix
    Dim im As Image
    Private Sub Form1_Load(ByVal sender As Object, ByVal e As  _
System.EventArgs) Handles Me.Load
        ' create your graphics object using this method
        gr = Me.CreateGraphics
        im = Image.FromFile("Write your Image directory here")
    End Sub


    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As  _
System.EventArgs) Handles Button1.Click
        'rotate matrix around specific point
        mat.RotateAt(30, New Point(100, 200))
        gr.Transform = mat
    End Sub

    Private Sub Form1_Paint(ByVal sender As Object, ByVal e As  _
 System.Windows.Forms.PaintEventArgs) Handles Me.Paint
        'very important to clear your device before drawing, choose any color to clear it
        gr.Clear(Color.Wheat)
        'image center match the rotation center
        gr.DrawImage(im, 75, 175, 50, 50)
    End Sub
End Class

you can have a look in my tutorial in directX transformation , i know it s different but you can get some usefull ideas Basic Directx Transformation with VB.NET

thanks anybody. I found the best way to resolve my problem and I think it is good.

Public Function RotateImg(ByVal bmpimage As Bitmap, ByVal angle As Single) As Bitmap
        Dim w As Integer = bmpimage.Width
        Dim h As Integer = bmpimage.Height
        Dim pf As PixelFormat = Nothing
        pf = bmpimage.PixelFormat
        Dim tempImg As New Bitmap(w, h, pf)
        Dim g As Graphics = Graphics.FromImage(tempImg)
        g.DrawImageUnscaled(bmpimage, 1, 1)
        g.Dispose()
        Dim path As New GraphicsPath()
        path.AddRectangle(New RectangleF(0.0F, 0.0F, w, h))
        Dim mtrx As New Matrix()
        'Using System.Drawing.Drawing2D.Matrix class
        
        mtrx.Rotate(angle)
        Dim rct As RectangleF = path.GetBounds(mtrx)
        Dim newImg As New Bitmap(Convert.ToInt32(rct.Width), Convert.ToInt32(rct.Height), pf)
        g = Graphics.FromImage(newImg)
        g.TranslateTransform(-rct.X, -rct.Y)
        g.RotateTransform(angle)
        g.InterpolationMode = InterpolationMode.HighQualityBilinear
        g.DrawImageUnscaled(tempImg, 0, 0)
        g.Dispose()
        tempImg.Dispose()
        Return newImg
    End Function

call this function:

Dim img As Bitmap
img = New Bitmap(My.Resources.bg4)
PictureBox1.Image = RotateImg(img, Convert.ToSingle(iAngel))

Some other links
Image Rotation in .NET[^]
http://www.dreamincode.net/code/snippet1512.htm[^]
http://www.devasp.net/net/articles/display/391.html[^]
http://www.xtremevbtalk.com/showthread.php?t=205134[^]