Private Sub Form_Load()
    Dim bvTMP()     As Byte
 
    Call LoadFile("C:\WINDOWS\SYSTEM32\CALC.EXE", bvTMP)
    Debug.Print Hex$(GetHash(bvTMP)),
    Call LoadFile("C:\WINDOWS\SYSTEM32\NOTEPAD.EXE", bvTMP)
    Debug.Print Hex$(GetHash(bvTMP))
End Sub
 
Public Function GetHash(ByRef bvArray() As Byte) As Double
    Dim i           As Long
 
    For i = LBound(bvArray) To UBound(bvArray)
        GetHash = GetHash + (bvArray(i) Xor (((GetHash And &HFFFF0000) \ &H10000) And &HFF))
    Next i
End Function
 
Public Sub LoadFile(ByVal sPath As String, ByRef bvRET() As Byte)
    Open sPath For Binary As #1
        ReDim bvRET(0 To LOF(1) - 1)
        Get #1, , bvRET
    Close #1
End Sub

Option Explicit

'GDI32
Private Declare Function GetBitmapBits Lib "GDI32" (ByVal hBitmap As Long, ByVal dwCount As Long, lpBits As Any) As Long
Private Declare Function GetObject Lib "GDI32" Alias "GetObjectA" (ByVal hObject As Long, ByVal nCount As Long, lpObject As Any) As Long

Private Type BITMAP
    bmType          As Long
    bmWidth         As Long
    bmHeight        As Long
    bmWidthBytes    As Long
    bmPlanes        As Integer
    bmBitsPixel     As Integer
    bmBits          As Long
End Type

Private Sub GetBitmapData(ByVal pPIC As PictureBox, ByRef bvRet() As Byte)
    Dim tBitmap       As BITMAP
   
    Call GetObject(pPIC.Image.Handle, Len(tBitmap), tBitmap)

    ReDim bvRet(0 To (tBitmap.bmWidth * 4) * tBitmap.bmHeight) As Byte
   
    Call GetBitmapBits(pPIC.Picture.Handle, UBound(bvRet), bvRet(0))
End Sub

Public Function GetHash(ByRef bvArray() As Byte) As Double
    Dim i           As Long
 
    For i = LBound(bvArray) To UBound(bvArray)
        GetHash = GetHash + (bvArray(i) Xor (((GetHash And &HFFFF0000) \ &H10000) And &HFF))
    Next i
End Function

Private Sub Form_Load()
    Dim p1()        As Byte
    Dim p2()        As Byte
   
    Call GetBitmapData(Picture1, p1)
    Call GetBitmapData(Picture2, p2)
   
    If GetHash(p1) = GetHash(p2) Then MsgBox "IGUALES!"
End Sub