Made the supported image formats extendable, and supplied a SVG implementation right away with the jira addon.

GreenshotPlugin/Core/IImage.cs

@@ -0,0 +1,68 @@
+/*
+ * Greenshot - a free and open source screenshot tool
+ * Copyright (C) 2007-2016 Thomas Braun, Jens Klingen, Robin Krom
+ * 
+ * For more information see: http://getgreenshot.org/
+ * The Greenshot project is hosted on GitHub https://github.com/greenshot/greenshot
+ * 
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 1 of the License, or
+ * (at your option) any later version.
+ * 
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+using System;
+using System.Drawing;
+using System.Drawing.Imaging;
+
+namespace GreenshotPlugin.Core
+{
+	/// <summary>
+	/// The image interface, this abstracts an image
+	/// </summary>
+	public interface IImage : IDisposable
+	{
+		/// <summary>
+		/// Height of the image, can be set to change
+		/// </summary>
+		int Height { get; set; }
+
+		/// <summary>
+		/// Width of the image, can be set to change.
+		/// </summary>
+		int Width { get; set; }
+
+		/// <summary>
+		/// Size of the image
+		/// </summary>
+		Size Size { get; }
+
+		/// <summary>
+		/// Pixelformat of the underlying image
+		/// </summary>
+		PixelFormat PixelFormat { get; }
+
+		/// <summary>
+		/// Vertical resolution of the underlying image
+		/// </summary>
+		float VerticalResolution { get; }
+
+		/// <summary>
+		/// Horizontal resolution of the underlying image
+		/// </summary>
+		float HorizontalResolution { get; }
+
+		/// <summary>
+		/// Unterlying image, or an on demand rendered version with different attributes as the original
+		/// </summary>
+		Image Image { get; }
+	}
+}