Public Sub Rotate(ByRef imgSrc As Image, ByVal Angle As Single, ByVal BackColor _
  As Color)
Dim dA As Double
Dim iPointsX(3) As Integer
Dim iPointsY(3) As Integer
Dim dR As Double = 0.5 * Math.Sqrt(Math.Pow(imgSrc.Height, 2) + Math.Pow( _
  imgSrc.Width, 2))
Dim dAngleRad As Double = Math.PI * Angle / 180
Dim iK As Integer = -1
For I As Integer = 1 To 4
dA = Math.PI * (I \ 3) + iK * Math.Atan(imgSrc.Height / imgSrc.Width)
iPointsX(I - 1) = dR * Math.Cos(dAngleRad + dA) + imgSrc.Width * 0.5
iPointsY(I - 1) = dR * Math.Sin(dAngleRad + dA) + imgSrc.Height * 0.5
iK *= -1
Next
Dim pts() As Point = {New Point(iPointsX(3), iPointsY(3)), New Point(iPointsX( _
  0), iPointsY(0)), New Point(iPointsX(2), iPointsY(2))}
Array.Sort(iPointsX)
Array.Sort(iPointsY)
Dim imgNew As Bitmap = New Bitmap(iPointsX(3) - iPointsX(0), iPointsY(3) - _
  iPointsY(0))
Dim graSrc As Graphics = Graphics.FromImage(imgNew)
graSrc.InterpolationMode = Drawing2D.InterpolationMode.HighQualityBicubic
graSrc.Clear(BackColor)
For I As Integer = 0 To 2
pts(I).X -= iPointsX(0)
pts(I).Y -= iPointsY(0)
Next
graSrc.DrawImage(imgSrc, pts)
graSrc.Dispose()
imgSrc = imgNew
End Sub