System.Drawing.Image image;
image = System.Drawing.Image.FromFile(_path);
int srcWidth = image.Width;
int srcHeight = image.Height;
/* explicity supply the thumbnail height and width so commented the code.
// if(srcHeight>srcWidth)
// thumbHeight=(srcHeight/srcWidth)*thumbWidth;
// else
// thumbHeight=(srcWidth/srcHeight)*thumbWidth;

System.Drawing.Bitmap bitmap = new System.Drawing.Bitmap(thumbWidth, (int)thumbHeight);

//- Create a System.Drawing.Graphics object from the Bitmap which we will use to draw the high quality scaled image
System.Drawing.Graphics gr = System.Drawing.Graphics.FromImage(bitmap);

//- Set the System.Drawing.Graphics object property SmoothingMode to HighQuality
gr.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;

//- Set the System.Drawing.Graphics object property CompositingQuality to HighQuality
gr.CompositingQuality = System.Drawing.Drawing2D.CompositingQuality.HighQuality;

//- Set the System.Drawing.Graphics object property InterpolationMode to High
gr.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High;

//- Draw the original image into the target Graphics object scaling to the desired width and height
System.Drawing.Rectangle rectDestination = new System.Drawing.Rectangle(0, 0, thumbWidth, (int)thumbHeight);

//Set Image codec of JPEG type, the index of JPEG codec is “1″

System.Drawing.Imaging.ImageCodecInfo codec = System.Drawing.Imaging.ImageCodecInfo.GetImageEncoders()[1];

//Set the parameters for defining the quality of the thumbnail… here it is set to 100%

System.Drawing.Imaging.EncoderParameters eParams = new System.Drawing.Imaging.EncoderParameters(1);

eParams.Param[0] = new System.Drawing.Imaging.EncoderParameter(System.Drawing.Imaging.Encoder.Quality, 100L);

gr.DrawImage(image, rectDestination, 0, 0, srcWidth, srcHeight, System.Drawing.GraphicsUnit.Pixel);

bitmap.Dispose();
image.Dispose();

context.Response.ContentType = “image/Jpeg”;
bitmap.Save(context.Response.OutputStream, ImageFormat.Jpeg);

Images are still blurred i can send you the code if these line supports your code.

Please reply as soos as possible.
Thanx