C#: Resize An Image While Maintaining Aspect Ratio and Maximum Height

cornerblue (CornerBLUE, Inc.) — Thu, 19 Jul 2007 22:55:39 GMT

// This allows us to resize the image. It prevents skewed images and
// also vertically long images caused by trying to maintain the aspect
// ratio on images who's height is larger than their width



public void ResizeImage(string OriginalFile, string NewFile, int NewWidth, int MaxHeight, bool OnlyResizeIfWider)

{

	System.Drawing.Image FullsizeImage = System.Drawing.Image.FromFile(OriginalFile);



	// Prevent using images internal thumbnail

	FullsizeImage.RotateFlip(System.Drawing.RotateFlipType.Rotate180FlipNone);

	FullsizeImage.RotateFlip(System.Drawing.RotateFlipType.Rotate180FlipNone);



	if (OnlyResizeIfWider)

	{

		if (FullsizeImage.Width <= NewWidth)

		{

			NewWidth = FullsizeImage.Width;

		}

	}



	int NewHeight = FullsizeImage.Height * NewWidth / FullsizeImage.Width;

	if (NewHeight > MaxHeight)

	{

		// Resize with height instead

		NewWidth = FullsizeImage.Width * MaxHeight / FullsizeImage.Height;

		NewHeight = MaxHeight;

	}



	System.Drawing.Image NewImage = FullsizeImage.GetThumbnailImage(NewWidth, NewHeight, null, IntPtr.Zero);



	// Clear handle to original file so that we can overwrite it if necessary

	FullsizeImage.Dispose();



	// Save resized picture

	NewImage.Save(NewFile);

}

Convert a number to its closest fraction

korakot (Korakot Chaovavanich) — Sun, 18 Sep 2005 15:08:27 GMT

Sometimes, I need to find a ratio approximation of a number.
Like 640 / 480 (vga) or similar number. I learn about farey
series a few years ago (1994).
The idea is actually quite simple.



>>> farey(math.pi,100)

(22, 7)

Get the implementation here.

DZone Snippets: ratio code

C#: Resize An Image While Maintaining Aspect Ratio and Maximum Height

Convert a number to its closest fraction