square.aspx - ritaglio immagine

[ser_god]

salve,
ho trovato questo utilissimo script che ritaglia l'immagine in un quadrato e me la ridimensiona secondo le mie esigenze.
avrei un questido da porvi: come per il webresize, vorrei sapere come posso gestire la qualità della jpg generata dallo script.
grazie per l'aiuto.

questo è il codice

<%@ Page Language="VB"%>
<%@ import Namespace="System.Drawing"%>
<%@ import Namespace="System.Drawing.Imaging"%>
<%@ import Namespace="System.Text.RegularExpressions"%>

<%
dim strFilename as string
dim i as System.Drawing.Image
dim b as System.Drawing.bitmap
dim g as graphics
If Left(request.QueryString("img"),4) = "http" then
    'Response.Write("case1
")
    strFilename=server.mappath(right(request.QueryString("img"),len(request.QueryString("img"))-len(Request.ServerVariables("SERVER_NAME"))-7))
else
    'Response.Write("case2
")
    strFilename = server.mappath(request.QueryString("img"))
end if
i = System.Drawing.Image.FromFile(strFilename)
b = New system.drawing.bitmap(request.QueryString("opx"), request.QueryString("opx"), pixelformat.format24bpprgb)
g = graphics.fromimage(b)
g.InterpolationMode = 2
g.SmoothingMode = 4
g.PixelOffsetMode = 4
g.CompositingQuality = 4

’ scale and translate the image
Dim NewLar, NewAlt, SrcX, SrcY
If i.height>i.width then
    NewLar = i.width
    NewAlt = i.width
    SrcX=0
    SrcY = (((i.height*request.QueryString("opx"))/i.width)-request.QueryString("opx"))/2
else
    NewLar = i.height
    NewAlt = i.height
    SrcY = 0
    SrcX = (((i.width*request.QueryString("opx"))/i.height)-request.QueryString("opx"))/2

end if
g.drawimage(i,New rectangle(0,0,request.QueryString("opx"),request.QueryString("opx")), New rectangle(SrcX,SrcY,NewLar,NewAlt), GraphicsUnit.Pixel)
'Response.Write(NewLar & " " & NewAlt & " " & SrcX & " " & SrcY)
response.contenttype="image/jpeg"
b.save(response.outputstream, imageformat.jpeg)
b.dispose() 
%>