Generating image thumbnails in ASP.NET?

Question

What is the fastest and more reliable way of generating thumbnails in .NET? I need to get any image, compress it in JPEG and resize it.

I\'ve seen several examples w

Answer 1

This has done me fine for years:

public static void CreateThumbnail(string filename, int desiredWidth, int desiredHeight, string outFilename)
{
    using (System.Drawing.Image img = System.Drawing.Image.FromFile(filename))
    {
        float widthRatio = (float)img.Width / (float)desiredWidth;
        float heightRatio = (float)img.Height / (float)desiredHeight;
        // Resize to the greatest ratio
        float ratio = heightRatio > widthRatio ? heightRatio : widthRatio;
        int newWidth = Convert.ToInt32(Math.Floor((float)img.Width / ratio));
        int newHeight = Convert.ToInt32(Math.Floor((float)img.Height / ratio));
        using (System.Drawing.Image thumb = img.GetThumbnailImage(newWidth, newHeight, new System.Drawing.Image.GetThumbnailImageAbort(ThumbnailImageAbortCallback), IntPtr.Zero))
        {
            thumb.Save(outFilename, System.Drawing.Imaging.ImageFormat.Jpeg);
        }
    }
}

public static bool ThumbnailImageAbortCallback()
{
    return true;
}