Generate High Quality Thumbnail

Hi,
I want to generate high quality thumbnail of the image. I want to do same functionality like ASPJPEG provide. The link is http://support.persits.com/jpeg/pick_jpeg.asp  .  I want the same like this.
I searched through but didn't find the solution. Some the links are below which generate images but not high quality images.
http://asptutorials.net/ASP/making-high-quality-image-thumbnails/

http://www.c-sharpcorner.com/Forums/ShowMessages.aspx?ThreadID=67296


Thanks in advance.....
Regards,

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