Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
   Dim bmp As New Bitmap("c:\1.bmp"
   Dim p As New Pixxxelz(bmp) : bmp.Dispose()
   For x As Integer = 0 To p.Width - 1
       For y As Integer = 0 To p.Height - 1
           Dim pix As Pixxxelz.ARGB = p.GetPixel(x, y)
           Dim gray As Byte = (0.299 * pix.r) + (0.587 * pix.g) + (0.114 * pix.b)
           Call p.SetPixel(x, y, New Pixxxelz.ARGB(255, gray, gray, gray))
       Next
   Next
   Me.WindowState = FormWindowState.Maximized
   Me.BackgroundImage = p.ToBitmap(True)
   p.Dispose()
   MsgBox("GRAYSCALE"
End Sub

Imports System.Drawing
Imports System.Drawing.Imaging
Imports System.Runtime.InteropServices

' Работаем с пикселами 32-битового изображения (Format32bppArgb)

Public Class Pixxxelz

' na http://sontse.hmarka.net/ abo http://igorr.zx6.ru/ ye pizdata demo programa i kucha raznogo ohuyennogo koda!

Implements ICloneable
Implements IDisposable

Public Declare Ansi Sub memcpy Lib "kernel32" Alias "RtlMoveMemory" _
       ByVal Dst As IntPtr, ByVal Src As IntPtr, ByVal Length As Integer)
Public Declare Ansi Sub memcpy2 Lib "kernel32" Alias "RtlMoveMemory" _
       ByVal Dst As Byte, ByVal Src As IntPtr, ByVal Length As Integer)
Public Declare Ansi Sub memcpy3 Lib "kernel32" Alias "RtlMoveMemory" _
       ByVal Dst As ARGB, ByVal Src As IntPtr, ByVal Length As Integer)

#Region " ARGB - структура работы с 32-битовым цветом (Drawing.Color - не годится)"

Public Structure ARGB

Dim b As Byte
Dim g As Byte
Dim r As Byte
Dim a As Byte

' Параметризированный конструктор

Public Sub New(ByVal a As Byte, ByVal r As Byte, ByVal g As Byte, ByVal b As Byte)
   Me.a = a : Me.r = r : Me.g = g : Me.b = b
End Sub

End Structure

#End Region

Friend _width As Integer
Friend _height As Integer
Friend _ptr As IntPtr
Friend _length As Integer

Public Sub New(ByVal img As Bitmap)
   MyBase.New()
   Dim tmp As New Bitmap(img.Width, img.Height, PixelFormat.Format32bppArgb)
   Dim g As Graphics = Graphics.FromImage(tmp)
   Call g.DrawImageUnscaled(img, 0, 0) : g.Dispose()
   _length = img.Width * img.Height * 4 ' Длина данных 32-битового изображения в памяти (4 байта на пиксел)
   _ptr = Marshal.AllocHGlobal(_length) ' Выделяем отдельно память
   ' Блокируем данные изображения
   Dim data As BitmapData = tmp.LockBits(New Rectangle(0, 0, tmp.Width, _
   tmp.Height), ImageLockMode.ReadOnly, PixelFormat.Format32bppArgb)
   Call memcpy(_ptr, data.Scan0, _length)
   Call tmp.UnlockBits(data) : tmp.Dispose()
   _width = img.Width : _height = img.Height
End Sub

Public Sub SetPixel(ByVal x As Integer, ByVal y As Integer, ByVal value As ARGB)
   Dim ofs As Integer = ((y * Width) + x) * 4
   Marshal.WriteByte(_ptr, ofs + 3, value.a)
   Marshal.WriteByte(_ptr, ofs + 2, value.r)
   Marshal.WriteByte(_ptr, ofs + 1, value.g)
   Marshal.WriteByte(_ptr, ofs, value.b)
End Sub

Public Function GetPixel(ByVal x As Integer, ByVal y As Integer) As ARGB
   Dim ofs As Integer = ((y * Width) + x) * 4
   Return New ARGB(Marshal.ReadByte(_ptr, ofs + 3), Marshal.ReadByte(_ptr, ofs + 2), _
   Marshal.ReadByte(_ptr, ofs + 1), Marshal.ReadByte(_ptr, ofs))
End Function

' Получить изображение
' (copy = false) - изображение на основе графической информации данного объекта
' (copy = true) - изображение на основе копии графической информации данного объекта
Public Function ToBitmap(Optional ByVal copy As Boolean = False) As Bitmap
   If copy Then
      Dim p As Pixxxelz = CType(Clone(), Pixxxelz)
      Return p.ToBitmap(False)
   Else
      Return New Bitmap(Width, Height, Width * 4, PixelFormat, Pointer)
   End If
End Function

Public ReadOnly Property Width() As Integer
 Get
    Return _width
 End Get
End Property

Public ReadOnly Property Height() As Integer
 Get
    Return _height
 End Get
End Property

Public ReadOnly Property Length() As Integer
 Get
    Return _length
 End Get
End Property

Public ReadOnly Property Pointer() As IntPtr
 Get
    Return _ptr
 End Get
End Property

Public ReadOnly Property PixelFormat() As PixelFormat
 Get
    Return Imaging.PixelFormat.Format32bppArgb
 End Get
End Property

#Region " для общего развития"

Public Shared Operator =(ByVal first As Pixxxelz, ByVal second As Pixxxelz) As Boolean
   Return first._ptr.ToInt32 = second._ptr.ToInt32
End Operator

Public Shared Operator <>ByVal first As Pixxxelz, ByVal second As Pixxxelz) As Boolean
   Return Not first = second
End Operator

Public Function Clone() As Object Implements System.ICloneable.Clone
   Dim pxlz As New Pixxxelz
   With pxlz
      ._ptr = Marshal.AllocHGlobal(_length)
      Call memcpy(._ptr, _ptr, _length)
      ._height = _height
      ._width = _width
      ._length = _length
   End With
   Return pxlz
End Function

Public Sub Dispose() Implements IDisposable.Dispose
   On Error GoTo nahuy
   Call Marshal.FreeHGlobal(_ptr)
   Finalize()
   Return
nahuy:
End Sub

Friend Sub New()
   MyBase.New()
End Sub

#End Region

Public Function ToByteArray() As Byte()
   Dim arr((Width * Height * 4) - 1) As Byte
   Call memcpy2(arr(0), Pointer, Length)
   Return arr
End Function

Public Function ToArgb() As ARGB()
   Dim arr((Width * Height) - 1) As ARGB
   Call memcpy3(arr(0), Pointer, Length)
   Return arr
End Function

End Class

Public Declare Ansi Sub memcpy2 Lib "kernel32" Alias "RtlMoveMemory" _
       ByVal Dst() As Byte, ByVal Src As IntPtr, ByVal Length As Integer)
Public Declare Ansi Sub memcpy3 Lib "kernel32" Alias "RtlMoveMemory" _
       ByVal Dst() As ARGB, ByVal Src As IntPtr, ByVal Length As Integer)

' и это

Public Function ToByteArray() As Byte()
   Dim arr((Width * Height * 4) - 1) As Byte
   Call memcpy2(arr, Pointer, Length)
   Return arr
End Function

Public Function ToArgb() As ARGB()
   Dim arr((Width * Height) - 1) As ARGB
   Call memcpy3(arr, Pointer, Length)
   Return arr
End Function