add missed file

src/ImageSharp/Common/Helpers/ExifResolutionValues.cs

@@ -0,0 +1,21 @@
+// Copyright (c) Six Labors.
+// Licensed under the Apache License, Version 2.0.
+
+namespace SixLabors.ImageSharp.Common.Helpers
+{
+    internal readonly struct ExifResolutionValues
+    {
+        public ExifResolutionValues(ushort resolutionUnit, double? horizontalResolution, double? verticalResolution)
+        {
+            this.ResolutionUnit = resolutionUnit;
+            this.HorizontalResolution = horizontalResolution;
+            this.VerticalResolution = verticalResolution;
+        }
+
+        public ushort ResolutionUnit { get; }
+
+        public double? HorizontalResolution { get; }
+
+        public double? VerticalResolution { get; }
+    }
+}