Moved synchronization code to the ExifProfile.

src/ImageSharp/MetaData/ImageMetaData.cs

@@ -142,28 +142,7 @@ namespace ImageSharp
         /// </summary>
         internal void SyncProfiles()
         {
-            this.SyncExifProfile();
-        }
-
-        private void SyncExifProfile()
-        {
-            if (this.ExifProfile == null)
-            {
-                return;
-            }
-
-            this.SyncExifResolution(ExifTag.XResolution, this.HorizontalResolution);
-            this.SyncExifResolution(ExifTag.YResolution, this.VerticalResolution);
-        }
-
-        private void SyncExifResolution(ExifTag tag, double resolution)
-        {
-            ExifValue value = this.ExifProfile.GetValue(tag);
-            if (value != null)
-            {
-                Rational newResolution = new Rational(resolution, false);
-                this.ExifProfile.SetValue(tag, newResolution);
-            }
+            this.ExifProfile?.Sync(this);
         }
     }
 }

src/ImageSharp/MetaData/Profiles/Exif/ExifProfile.cs

@@ -224,6 +224,26 @@ namespace ImageSharp
             return writer.GetData();
         }
 
+        /// <summary>
+        /// Synchronizes the profiles with the specified meta data.
+        /// </summary>
+        /// <param name="metaData">The meta data.</param>
+        internal void Sync(ImageMetaData metaData)
+        {
+            this.SyncResolution(ExifTag.XResolution, metaData.HorizontalResolution);
+            this.SyncResolution(ExifTag.YResolution, metaData.VerticalResolution);
+        }
+
+        private void SyncResolution(ExifTag tag, double resolution)
+        {
+            ExifValue value = this.GetValue(tag);
+            if (value != null)
+            {
+              Rational newResolution = new Rational(resolution, false);
+              this.SetValue(tag, newResolution);
+            }
+        }
+
         private void InitializeValues()
         {
             if (this.values != null)

tests/ImageSharp.Tests/MetaData/ImageMetaDataTests.cs

@@ -80,28 +80,13 @@ namespace ImageSharp.Tests
 
             Image image = new Image(1, 1);
             image.MetaData.ExifProfile = exifProfile;
-            image.MetaData.HorizontalResolution = 200;
-            image.MetaData.VerticalResolution = 300;
-
-            image.MetaData.HorizontalResolution = 100;
-
-            Assert.Equal(200, ((Rational)image.MetaData.ExifProfile.GetValue(ExifTag.XResolution).Value).ToDouble());
-            Assert.Equal(300, ((Rational)image.MetaData.ExifProfile.GetValue(ExifTag.YResolution).Value).ToDouble());
-
-            image.MetaData.SyncProfiles();
-
-            Assert.Equal(100, ((Rational)image.MetaData.ExifProfile.GetValue(ExifTag.XResolution).Value).ToDouble());
-            Assert.Equal(300, ((Rational)image.MetaData.ExifProfile.GetValue(ExifTag.YResolution).Value).ToDouble());
-
-            image.MetaData.VerticalResolution = 150;
-
-            Assert.Equal(100, ((Rational)image.MetaData.ExifProfile.GetValue(ExifTag.XResolution).Value).ToDouble());
-            Assert.Equal(300, ((Rational)image.MetaData.ExifProfile.GetValue(ExifTag.YResolution).Value).ToDouble());
+            image.MetaData.HorizontalResolution = 400;
+            image.MetaData.VerticalResolution = 500;
 
             image.MetaData.SyncProfiles();
 
-            Assert.Equal(100, ((Rational)image.MetaData.ExifProfile.GetValue(ExifTag.XResolution).Value).ToDouble());
-            Assert.Equal(150, ((Rational)image.MetaData.ExifProfile.GetValue(ExifTag.YResolution).Value).ToDouble());
+            Assert.Equal(400, ((Rational)image.MetaData.ExifProfile.GetValue(ExifTag.XResolution).Value).ToDouble());
+            Assert.Equal(500, ((Rational)image.MetaData.ExifProfile.GetValue(ExifTag.YResolution).Value).ToDouble());
         }
     }
 }

tests/ImageSharp.Tests/MetaData/Profiles/Exif/ExifProfileTests.cs

@@ -203,6 +203,39 @@ namespace ImageSharp.Tests
             Assert.Equal(7, image.MetaData.ExifProfile.Values.Count());
         }
 
+        [Fact]
+        public void Syncs()
+        {
+            ExifProfile exifProfile = new ExifProfile();
+            exifProfile.SetValue(ExifTag.XResolution, new Rational(200));
+            exifProfile.SetValue(ExifTag.YResolution, new Rational(300));
+
+            ImageMetaData metaData = new ImageMetaData();
+            metaData.ExifProfile = exifProfile;
+            metaData.HorizontalResolution = 200;
+            metaData.VerticalResolution = 300;
+
+            metaData.HorizontalResolution = 100;
+
+            Assert.Equal(200, ((Rational)metaData.ExifProfile.GetValue(ExifTag.XResolution).Value).ToDouble());
+            Assert.Equal(300, ((Rational)metaData.ExifProfile.GetValue(ExifTag.YResolution).Value).ToDouble());
+
+            exifProfile.Sync(metaData);
+
+            Assert.Equal(100, ((Rational)metaData.ExifProfile.GetValue(ExifTag.XResolution).Value).ToDouble());
+            Assert.Equal(300, ((Rational)metaData.ExifProfile.GetValue(ExifTag.YResolution).Value).ToDouble());
+
+            metaData.VerticalResolution = 150;
+
+            Assert.Equal(100, ((Rational)metaData.ExifProfile.GetValue(ExifTag.XResolution).Value).ToDouble());
+            Assert.Equal(300, ((Rational)metaData.ExifProfile.GetValue(ExifTag.YResolution).Value).ToDouble());
+
+            exifProfile.Sync(metaData);
+
+            Assert.Equal(100, ((Rational)metaData.ExifProfile.GetValue(ExifTag.XResolution).Value).ToDouble());
+            Assert.Equal(150, ((Rational)metaData.ExifProfile.GetValue(ExifTag.YResolution).Value).ToDouble());
+        }
+
         [Fact]
         public void Values()
         {