http://stackoverflow.com/questions/3115076/adjust-the-contrast-of-an-image-in-c-sharp-efficiently[
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solution for above question is not working in vb 2005
i need solution in vb2005
below is vb2005 code
Public Shared Function AdjustContrast(Image As Bitmap, Value As Single) As Bitmap
Value = (100F + Value) / 100F
Value *= Value
Dim NewBitmap As Bitmap = DirectCast(Image.Clone(), Bitmap)
Dim data As BitmapData = NewBitmap.LockBits(New Rectangle(0, 0, NewBitmap.Width, NewBitmap.Height), ImageLockMode.ReadWrite, NewBitmap.PixelFormat)
For y As Integer = 0 To NewBitmap.Height - 1
Dim row As Pointer(Of Byte) = CType(data.Scan0, Pointer(Of Byte)) + (y * data.Stride)
Dim columnOffset As Integer = 0
For x As Integer = 0 To NewBitmap.Width - 1
Dim B As Byte = row(columnOffset)
Dim G As Byte = row(columnOffset + 1)
Dim R As Byte = row(columnOffset + 2)
Dim Red As Single = R / 255F
Dim Green As Single = G / 255F
Dim Blue As Single = B / 255F
Red = (((Red - 0.5F) * Value) + 0.5F) * 255F
Green = (((Green - 0.5F) * Value) + 0.5F) * 255F
Blue = (((Blue - 0.5F) * Value) + 0.5F) * 255F
Dim iR As Integer = CInt(Red)
iR = If(iR > 255, 255, iR)
iR = If(iR < 0, 0, iR)
Dim iG As Integer = CInt(Green)
iG = If(iG > 255, 255, iG)
iG = If(iG < 0, 0, iG)
Dim iB As Integer = CInt(Blue)
iB = If(iB > 255, 255, iB)
iB = If(iB < 0, 0, iB)
row(columnOffset) = CByte(iB)
row(columnOffset + 1) = CByte(iG)
row(columnOffset + 2) = CByte(iR)
columnOffset += 4
Next
Next
NewBitmap.UnlockBits(data)
Return NewBitmap
End Function
pointer(of byte) gives error
pls help