C# 이미지 리사이즈(비율 유지)

ImageConvertor.cs

using System;
using System.Drawing;

namespace ImageConvertor {
	class ImageConvertor {

		/**
		 * <summary>
		 * 이미지를 targetX, targetY로 리사이징함. 비율은 유지하고 빈 공간은 검은색으로 채움
		 * </summary>
		 */
		public static void Resize(string importPath, string exportPath, int targetX, int targetY) {
			Image originalImage = Image.FromFile(importPath);

			double ratioX = targetX / (double)originalImage.Width;
			double ratioY = targetY / (double)originalImage.Height;

			double ratio = Math.Min(ratioX, ratioY);

			int newWidth = (int)(originalImage.Width * ratio);
			int newHeight = (int)(originalImage.Height * ratio);

			Bitmap newImage = new Bitmap(targetX, targetY);
			using (Graphics g = Graphics.FromImage(newImage)) {
				g.FillRectangle(Brushes.Black, 0, 0, newImage.Width, newImage.Height);
				g.DrawImage(originalImage, (targetX - newWidth) / 2, (targetY - newHeight) / 2, newWidth, newHeight);
			}

			newImage.Save(exportPath);

			originalImage.Dispose();
			newImage.Dispose();
		}
	}
}