Resizing Images Without Components

[eglons]

Hi,

I've put a site together for a client, who now wants to Content Manage both the text and images. Text isn't a problem and I've implemented this, image replacement again isn't a problem, but I'm worried that they will simply upload 1Mb photos from their camera and wonder why the performance goes down the pan. I've used ASPJpeg on another project, but this site is on shared hosting anf they wont install components, so does anyone have a direct ASP code way of resizing and optimising images ?

Thanks in advance.

[menon]

Hi Guys!

create a file 'thumbnail.aspx' and insert the code

<%@ 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["img"]);
reqHeight = Convert.ToInt32("59"); //
reqWidth = Convert.ToInt32("100");
forceaspect = Convert.ToBoolean("False");


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(24, 24); //use this line for lower resolution thumbnails
outputImage.SetResolution(72, 72);

//outputImage.InterpolationMode = InterpolationMode.HighQualityBicubic;
System.Drawing.Imaging.ImageFormat outputFormat = (System.Drawing.Imaging.ImageFormat)imageOutputFor matsTable[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["img"]);
}
catch{}
finally{sw.Close();}
//now display the error image
Response.Redirect("images/thumberror.gif");
}
}
</script>


and you call call the thumbnail image by using this tag
<img border="0" src="thumbnail.aspx?img=/images/photo.jpg">

best regards,
Kalipurayath Sanal Menon