I have a function that I wrote that add transparency to a
System.Drawing.Image. When using this function on my webhost, I receive the
error

SecurityException: System.Security.Permissions.SecurityPermission

I am still able to generate graphics, but if I use this function I receive
this error. The function does not attempt to access any other files or
resources, and it works when testing it locally. My webhost is
myhosting.com, and the code for my function (which can also be seen on my
website) is:

Imports System.Drawing
Imports System.Drawing.Imaging
Namespace NathanSokalski
Public Class Transparency
 Public Shared Function MakeTransparent(ByVal oldbmp As Bitmap, ByVal
transparentcolor As Color) As Bitmap
  Dim bmp As New Bitmap(oldbmp.Width, oldbmp.Height,
PixelFormat.Format8bppIndexed)
  Dim palette As ColorPalette = bmp.Palette
  Dim nextindex As Byte = 0
  Dim bmpdata As BitmapData = bmp.LockBits(New Rectangle(0, 0,
oldbmp.Width, oldbmp.Height), ImageLockMode.WriteOnly,
PixelFormat.Format8bppIndexed)
  Dim index As Integer
  For i As UShort = 0 To 255
   palette.Entries(i) = Color.Empty
  Next
  For y As Integer = 0 To oldbmp.Height - 1
   For x As Integer = 0 To oldbmp.Width - 1
    'Get the palette index of the current pixel
    index = Transparency.InPalette(palette, nextindex, oldbmp.GetPixel(x,
y))
    'If the color is not in the palette, add it at the next unused index
    If index = -1 Then
     palette.Entries(nextindex) = oldbmp.GetPixel(x, y)
     index = nextindex
     nextindex += CByte(1)
    End If
    'Set the pixel to the proper index
    System.Runtime.InteropServices.Marshal.WriteByte(bmpdata.Scan0, y *
bmpdata.Stride + x, CByte(index))
   Next
  Next
  bmp.UnlockBits(bmpdata)
  'If the specified transparent color is included in the palette, change
that color to transparent
  If transparentcolor <> Color.Empty AndAlso
Transparency.InPalette(palette, nextindex - CByte(1), transparentcolor)
<> -1 Then palette.Entries(Transparency.InPalette(palette, nextindex -
CByte(1), transparentcolor)) = Color.FromArgb(0, 0, 0, 0)
  bmp.Palette = palette
  Return bmp
 End Function

 'Returns number of colors in bitmap
 Public Shared Function ColorCount(ByVal bmp As Bitmap) As Integer
  Dim palette As New Collections.ObjectModel.Collection(Of Integer)
  Dim currcolor As Integer
  For y As Integer = 0 To bmp.Height - 1
   For x As Integer = 0 To bmp.Width - 1
    currcolor = bmp.GetPixel(x, y).ToArgb()
    If Not palette.Contains(currcolor) Then palette.Add(currcolor)
   Next
  Next
  Return palette.Count
 End Function

 'Returns index of color in palette or -1
 Private Shared Function InPalette(ByVal palette As ColorPalette, ByVal
maxindex As Byte, ByVal colortofind As Color) As Integer
  For i As Byte = 0 To maxindex
   If palette.Entries(i).ToArgb() = colortofind.ToArgb() Then Return
CInt(i)
  Next
  Return -1
 End Function
End Class
End Namespace

Can anyone tell me a way to avoid this (or if there isn't one, a webhost
that doesn't prevent me from doing it)? myhosting.com's security policy for
ASP.NET 2.0 can be seen at:

https://support.myhosting.com/CustomerCare/KnowledgeBase/Article.asp?url=Documen
ts/ASP/Where%2520can%2520I%2520find%2520more%2520details%2520about%2520your%2520
dot-NET%2520Security%2520Policy.htm

Thanks.
--
Nathan Sokalski
njsokalski@hotmail.com
http://www.nathansokalski.com/