[RESOLVED] About ScaleGray

[joaquim]

i have these function for do scalegray:

Private Type BITMAPINFO
    bmiHeader As BITMAPINFOHEADER
    bmiColors As RGBQUAD
End Type

Private Const DIB_RGB_COLORS = 0&
Private Const BI_RGB = 0&

Private Const pixR As Integer = 3
Private Const pixG As Integer = 2
Private Const pixB As Integer = 1

'Put the image black and white
Public Sub MakeGray(ByVal picColor As PictureBox)
    Dim bitmap_info As BITMAPINFO
    Dim pixels() As Byte
    Dim bytes_per_scanLine As Integer
    Dim pad_per_scanLine As Integer
    Dim X As Integer
    Dim Y As Integer
    Dim ave_color As Byte

    ' Prepare the bitmap description.
    With bitmap_info.bmiHeader
        .biSize = 40
        .biWidth = picColor.ScaleWidth
        ' Use negative height to scan top-down.
        .biHeight = -picColor.ScaleHeight
        .biPlanes = 1
        .biBitCount = 32
        .biCompression = BI_RGB
        bytes_per_scanLine = ((((.biWidth * .biBitCount) + 31) \ 32) * 4)
        pad_per_scanLine = bytes_per_scanLine - (((.biWidth * .biBitCount) + 7) \ 8)
        .biSizeImage = bytes_per_scanLine * Abs(.biHeight)
    End With

    ' Load the bitmap's data.
    ReDim pixels(1 To 4, 1 To picColor.ScaleWidth, 1 To picColor.ScaleHeight)
    GetDIBits picColor.hdc, picColor.Image, _
        0, picColor.ScaleHeight, pixels(1, 1, 1), _
        bitmap_info, DIB_RGB_COLORS

    ' Modify the pixels.
    For Y = 1 To picColor.ScaleHeight
        For X = 1 To picColor.ScaleWidth
            ave_color = CByte((CInt(pixels(pixR, X, Y)) + _
                pixels(pixG, X, Y) + _
                pixels(pixB, X, Y)) \ 3)
            pixels(pixR, X, Y) = ave_color
            pixels(pixG, X, Y) = ave_color
            pixels(pixB, X, Y) = ave_color
        Next X
    Next Y

    ' Display the result.
    SetDIBits picColor.hdc, picColor.Image, _
        0, picColor.ScaleHeight, pixels(1, 1, 1), _
        bitmap_info, DIB_RGB_COLORS
    picColor.Picture = picColor.Image
End Sub

the picturebox that i use are both pixel scalemode.
in images(*.gif(animated and static); *.ico;*.ani;*.cur and others) is working ok.
but i'm using a strips images too(is a big image that have very subimages and the plus images can do an animation). for use these subimages i use the transparentbl() api function.
in these images(strips) these function doesn't the normal way, can anyone
heres the image for see...
has you can see the 1st, 2nd and 4th are ok, but the 3rd isn't...
can anyone explain to me why?
thanks