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

GreenshotPlugin/Core/ImageWrapper.cs

@@ -0,0 +1,86 @@
+using System.Drawing;
+using System.Drawing.Imaging;
+
+namespace GreenshotPlugin.Core
+{
+	/// <summary>
+	/// Wrap an image, make it resizeable
+	/// </summary>
+	public class ImageWrapper : IImage
+	{
+		// Underlying image, is used to generate a resized version of it when needed
+		private readonly Image _image;
+		private Image _imageClone;
+
+		/// <summary>
+		/// Factory method
+		/// </summary>
+		/// <param name="image">Image</param>
+		/// <returns>IImage</returns>
+		public static IImage FromImage(Image image)
+		{
+			return image == null ? null : new ImageWrapper(image);
+		}
+
+		public ImageWrapper(Image image)
+		{
+			// Make sure the orientation is set correctly so Greenshot can process the image correctly
+			ImageHelper.Orientate(image);
+			_image = image;
+			Width = _image.Width;
+			Height = _image.Height;
+		}
+
+		public void Dispose()
+		{
+			_image.Dispose();
+			_imageClone?.Dispose();
+		}
+
+		/// <summary>
+		/// Height of the image, can be set to change
+		/// </summary>
+		public int Height { get; set; }
+
+		/// <summary>
+		/// Width of the image, can be set to change.
+		/// </summary>
+		public int Width { get; set; }
+
+		/// <summary>
+		/// Size of the image
+		/// </summary>
+		public Size Size => new Size(Width, Height);
+
+		/// <summary>
+		/// Pixelformat of the underlying image
+		/// </summary>
+		public PixelFormat PixelFormat => Image.PixelFormat;
+
+		public float HorizontalResolution => Image.HorizontalResolution;
+		public float VerticalResolution => Image.VerticalResolution;
+
+		public Image Image
+		{
+			get
+			{
+				if (_imageClone == null)
+				{
+					if (_image.Height == Height && _image.Width == Width)
+					{
+						return _image;
+					}
+				}
+				if (_imageClone?.Height == Height && _imageClone?.Width == Width)
+				{
+					return _imageClone;
+				}
+				// Calculate new image clone
+				_imageClone?.Dispose();
+				_imageClone = ImageHelper.ResizeImage(_image, false, Width, Height, null);
+				return _imageClone;
+			}
+		}
+
+	}
+}