Proportionally Resize Bitmap

1.import two namespace

using System.Drawing;

using System.Drawing.Imaging;

2.Write the function

public Bitmap ProportionallyResizeBitmap(Bitmap src, int maxWidth, int maxHeight) {

	// original dimensions

	int w = src.Width;
	int h = src.Height;

	// Longest and shortest dimension

	int longestDimension = (w > h) ? w : h;
	int shortestDimension = (w < h) ? w : h;

	// propotionality

	float factor = ((float)longestDimension) / shortestDimension;

	// default width is greater than height

	double newWidth = maxWidth;
	double newHeight = maxWidth / factor;

	// if height greater than width recalculate

	if (w < h) {

		newWidth = maxHeight / factor;
		newHeight = maxHeight;

	}

	// Create new Bitmap at new dimensions

	Bitmap result = new Bitmap((int)newWidth, (int)newHeight);
	using (Graphics g = Graphics.FromImage((System.Drawing.Image)result))
	g.DrawImage(src, 0, 0, (int)newWidth, (int)newHeight);

	return result;

}

3.At the time call function write

if (fuImageFile.HasFile) {

	string fileName = fuImageFile.FileName;

	// Get the bitmap data from the uploaded file

	Bitmap src = Bitmap.FromStream(fuImageFile.PostedFile.InputStream) as Bitmap;

	// Resize the bitmap data

	Bitmap result = ProportionallyResizeBitmap(src, 630, 252);

	string saveName = Server.MapPath(savePath) + fileName;

	result.Save(saveName, ImageFormat.Jpeg);

	tbbanner.BANNER_IMAGE = fileName;

}