این کد را نگاه کنید
string path = @"e:\\Class.Browser16.png";
Image large = Image.FromFile(path, true);
int x = 0;
int y = 0;
int width = 16;
int height = 16;
int count = large.Width / width;
Bitmap bmp = new Bitmap(width, height);
Graphics g = Graphics.FromImage(bmp);
for (int i = 0; i < count; i++ )
{
g.Clear(Color.Transparent);
g.DrawImage(large, new Rectangle(0, 0, width, height), new Rectangle(x, y, width, height), GraphicsUnit.Pixel);
bmp.Save(Path.ChangeExtension(path, String.Format(".{0}.bmp",i)));
x += width;
}