A thumbnail conversion script

[David R.]

I found a script that converts a regular size image to a thumbnail. It's a
wonderful script, except the thumbnail quality is a bit low.

I'd like to add the following code to improve the output quality of the
thumbnail. Can someone direct me where to incorporate this code? Thanks.

Code to insert:

graphic.InterpolationMode = InterpolationMode.HighQualityBicubic;
graphic.SmoothingMode = SmoothingMode.HighQuality;
graphic.PixelOffsetMode = PixelOffsetMode.HighQuality;
graphic.CompositingQuality = CompositingQuality.HighQuality;


Original script:

<%@ Page Language="C#" ContentType="text/html" ResponseEncoding="iso-8859-1"
%>
<script language="C#" runat="server">
void Page_Load(Object sender, EventArgs e)
{
try{
Response.Cache.VaryByParams["Image;Width;Height;ForceAspect"] = true;
Response.ContentType = "image/jpeg";
System.Collections.Hashtable imageOutputFormatsTable = new
System.Collections.Hashtable();
imageOutputFormatsTable.Add(System.Drawing.Imaging.ImageFormat.Gif.Guid,
System.Drawing.Imaging.ImageFormat.Gif);
imageOutputFormatsTable.Add(System.Drawing.Imaging.ImageFormat.Jpeg.Guid,
System.Drawing.Imaging.ImageFormat.Jpeg);
imageOutputFormatsTable.Add(System.Drawing.Imaging.ImageFormat.Bmp.Guid,
System.Drawing.Imaging.ImageFormat.Gif);
imageOutputFormatsTable.Add(System.Drawing.Imaging.ImageFormat.Tiff.Guid,
System.Drawing.Imaging.ImageFormat.Jpeg);
imageOutputFormatsTable.Add(System.Drawing.Imaging.ImageFormat.Png.Guid,
System.Drawing.Imaging.ImageFormat.Jpeg);

string imageLocation;
bool forceaspect = true;
int newHeight;
int newWidth;
int reqHeight = 100;
int reqWidth = 100;
int origHeight;
int origWidth;

imageLocation = Server.MapPath(Request.QueryString["Image"]);
if (Request.QueryString["Height"] != null){
reqHeight = Convert.ToInt32(Request.QueryString["Height"]);
}
if (Request.QueryString["ForceAspect"] != null){
forceaspect = Convert.ToBoolean(Request.QueryString["ForceAspect"]);
}
if(Request.QueryString["Width"] != null){
reqWidth = Convert.ToInt32(Request.QueryString["Width"]);
}
if (Request.QueryString["ForceAspect"] == "true"){
forceaspect = true;
}

System.Drawing.Bitmap origBitmap = new
System.Drawing.Bitmap(imageLocation);
origHeight = origBitmap.Height;
origWidth = origBitmap.Width;

if (forceaspect){
//Force Aspect Change
newHeight = reqHeight;
newWidth = reqWidth;
}
else if (origBitmap.Height >= origBitmap.Width){
//Portrait
newHeight = reqHeight;
newWidth = (int)(((double)origBitmap.Width / (double)origBitmap.Height) *
reqHeight);
}
else{
//Landscape
newWidth = reqWidth;
newHeight = (int)(((double)origBitmap.Height / (double)origBitmap.Width)
* reqWidth);
}

System.Drawing.Bitmap outputImage = new System.Drawing.Bitmap(origBitmap,
newWidth, newHeight);
outputImage.SetResolution(72, 72);

//outputImage.InterpolationMode = InterpolationMode.HighQualityBicubic;
// does not work
System.Drawing.Imaging.ImageFormat outputFormat =
(System.Drawing.Imaging.ImageFormat)imageOutputFormatsTable[origBitmap.RawFormat.Guid];

outputImage.Save(Response.OutputStream, outputFormat);
outputImage.Dispose();
origBitmap.Dispose();
}
catch (Exception ex){
//log error so we may know the problem. you need to have write permits, of
course on log path
System.IO.StreamWriter sw=null;
try{
sw=new System.IO.StreamWriter(Server.MapPath("error.txt"),true);
sw.WriteLine("Error : " + ex.Message + " processing " +
Request.QueryString["Image"]);
}
catch{}
finally{sw.Close();}
//now display the error image
Response.Redirect("thumberror.gif");
}
}
</script>