1public bool MakeThumbnail(string thumb, string img, int width, int height, bool keepOriginalRatio)
2    {
3        System.Drawing.Image fullSizeImg;
4        try
5        {
6            fullSizeImg = new System.Drawing.Bitmap(img);
7        }
8        catch (Exception ex)
9        {
10            return false;
11        }
12
13        if ((fullSizeImg.Width <= width) && (fullSizeImg.Height <= height))
14        {
15            //Smaller or same size as thumbnail so no need to do anything special 

16            try 
17            {
18                fullSizeImg.Save(thumb);
19                return true;
20            }
21            catch (Exception ex)
22            {
23                return false;
24            }
25        }
26        else
27        {
28            if (keepOriginalRatio)
29            {
30                if (width <= 0) 
31                {
32                    width = height * fullSizeImg.Width / fullSizeImg.Height;
33                }
34                else if (height <= 0)
35                {
36                    height = width * fullSizeImg.Height / fullSizeImg.Width;
37                }
38                else
39                {
40                    float TargetRatio = width / height;
41                    float CurrentRatio = fullSizeImg.Width / fullSizeImg.Height;
42                    
43                    if (CurrentRatio > TargetRatio) //We'll scale height 

44                    { height = width / Convert.ToInt16(CurrentRatio); } 
45                    else // We'll scale width 

46                    { width = height * Convert.ToInt16(CurrentRatio); }
47                }
48            }
49
50            System.Drawing.Image thumbNailImg = new System.Drawing.Bitmap(fullSizeImg, width, height);
51            System.Drawing.Graphics g = System.Drawing.Graphics.FromImage(thumbNailImg);
52
53            g.FillRectangle(System.Drawing.Brushes.White, 0, 0, width, height);
54            g.DrawImage(fullSizeImg, 0, 0, width, height);
55
56            try 
57            {
58                thumbNailImg.Save(thumb, fullSizeImg.RawFormat);
59            }
60            catch (Exception ex)
61            {
62                return false;
63            }
64        }
65        return false;
66    }