GrayScale Images

[PaulJayKnight]

Is there a way to convert an Image to Black and white before displaying it in a PictureBox?
Or is there a way to make a PictureBox display color images in black and white?

[dglienna]

Convert the image. (I'd keep two copies)

Public Function PureBW(ByVal image As System.Drawing.Bitmap, Optional ByVal Mode As BWMode = BWMode.By_Lightness, Optional ByVal tolerance As Single = 0) As System.Drawing.Bitmap
Dim x As Integer
Dim y As Integer
If tolerance > 1 Or tolerance < -1 Then
Throw New ArgumentOutOfRangeException
Exit Function
End If
For x = 0 To image.Width - 1 Step 1
For y = 0 To image.Height - 1 Step 1
Dim clr As Color = image.GetPixel(x, y)
If Mode = BWMode.By_RGB_Value Then
If (CInt(clr.R) + CInt(clr.G) + CInt(clr.B)) > 383 - (tolerance * 383) Then
image.SetPixel(x, y, Color.White)
Else
image.SetPixel(x, y, Color.Black)
End If
Else
If clr.GetBrightness > 0.5 - (tolerance / 2) Then
image.SetPixel(x, y, Color.White)
Else
image.SetPixel(x, y, Color.Black)
End If
End If
Next
Next
Return image
End Function
Enum BWMode
By_Lightness
By_RGB_Value
End Enum