Merge branch 'master' into js/fix-260

src/ImageSharp/Processing/Processors/Transforms/RotateProcessor.cs

@@ -7,6 +7,7 @@ using System.Threading.Tasks;
 using SixLabors.ImageSharp.Advanced;
 using SixLabors.ImageSharp.Helpers;
 using SixLabors.ImageSharp.Memory;
+using SixLabors.ImageSharp.MetaData.Profiles.Exif;
 using SixLabors.ImageSharp.PixelFormats;
 using SixLabors.Primitives;
 
@@ -87,6 +88,30 @@ namespace SixLabors.ImageSharp.Processing.Processors
             }
         }
 
+        /// <inheritdoc/>
+        protected override void AfterImageApply(Image<TPixel> source, Rectangle sourceRectangle)
+        {
+            ExifProfile profile = source.MetaData.ExifProfile;
+            if (profile == null)
+            {
+                return;
+            }
+
+            if (MathF.Abs(this.Angle) < Constants.Epsilon)
+            {
+                // No need to do anything so return.
+                return;
+            }
+
+            profile.RemoveValue(ExifTag.Orientation);
+
+            if (this.Expand && profile.GetValue(ExifTag.PixelXDimension) != null)
+            {
+                profile.SetValue(ExifTag.PixelXDimension, source.Width);
+                profile.SetValue(ExifTag.PixelYDimension, source.Height);
+            }
+        }
+
         /// <summary>
         /// Rotates the images with an optimized method when the angle is 90, 180 or 270 degrees.
         /// </summary>

src/ImageSharp/Quantizers/OctreeQuantizer{TPixel}.cs

@@ -61,6 +61,7 @@ namespace SixLabors.ImageSharp.Quantizers
             this.colors = (byte)maxColors.Clamp(1, 255);
             this.octree = new Octree(this.GetBitsNeededForColorDepth(this.colors));
             this.palette = null;
+            this.colorMap.Clear();
 
             return base.Quantize(image, this.colors);
         }

src/ImageSharp/Quantizers/PaletteQuantizer{TPixel}.cs

@@ -58,6 +58,7 @@ namespace SixLabors.ImageSharp.Quantizers
         public override QuantizedImage<TPixel> Quantize(ImageFrame<TPixel> image, int maxColors)
         {
             Array.Resize(ref this.colors, maxColors.Clamp(1, 255));
+            this.colorMap.Clear();
             return base.Quantize(image, maxColors);
         }
 

src/ImageSharp/Quantizers/QuantizerBase{TPixel}.cs

@@ -43,7 +43,7 @@ namespace SixLabors.ImageSharp.Quantizers.Base
         public bool Dither { get; set; } = true;
 
         /// <inheritdoc />
-        public IErrorDiffuser DitherType { get; set; } = new SierraLiteDiffuser();
+        public IErrorDiffuser DitherType { get; set; } = new FloydSteinbergDiffuser();
 
         /// <inheritdoc/>
         public virtual QuantizedImage<TPixel> Quantize(ImageFrame<TPixel> image, int maxColors)

src/ImageSharp/Quantizers/WuQuantizer{TPixel}.cs

@@ -139,6 +139,7 @@ namespace SixLabors.ImageSharp.Quantizers
 
             this.colors = maxColors.Clamp(1, 255);
             this.palette = null;
+            this.colorMap.Clear();
 
             try
             {