Removed precision parameter, removed YccK color space

src/ImageSharp/Formats/Jpeg/Components/Decoder/ColorConverters/JpegColorConverter.FromYCbCrScalar.cs

@@ -67,8 +67,8 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.Components.Decoder.ColorConverters
                     // cb = 128 - (0.168736 * r) - (0.331264 * g) + (0.5 * b)
                     // cr = 128 + (0.5 * r) - (0.418688 * g) - (0.081312 * b)
                     c0[i] = (0.299f * r) + (0.587f * g) + (0.114f * b);
-                    c1[i] = 128 - (0.168736f * r) - (0.331264f * g) + (0.5f * b);
+                    c1[i] = halfValue - (0.168736f * r) - (0.331264f * g) + (0.5f * b);
-                    c2[i] = 128 + (0.5f * r) - (0.418688f * g) - (0.081312f * b);
+                    c2[i] = halfValue + (0.5f * r) - (0.418688f * g) - (0.081312f * b);
                 }
             }
         }

src/ImageSharp/Formats/Jpeg/Components/Decoder/ColorConverters/JpegColorConverter.FromYccKScalar.cs

@@ -15,9 +15,12 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.Components.Decoder.ColorConverters
             }
 
             public override void ConvertToRgbInplace(in ComponentValues values) =>
-                ConvertCoreInplace(values, this.MaximumValue, this.HalfValue);
+                ConvertToRgpInplace(values, this.MaximumValue, this.HalfValue);
 
-            internal static void ConvertCoreInplace(in ComponentValues values, float maxValue, float halfValue)
+            public override void ConvertFromRgbInplace(in ComponentValues values)
+                => throw new NotImplementedException();
+
+            public static void ConvertToRgpInplace(in ComponentValues values, float maxValue, float halfValue)
             {
                 Span<float> c0 = values.Component0;
                 Span<float> c1 = values.Component1;
@@ -38,8 +41,6 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.Components.Decoder.ColorConverters
                     c2[i] = (maxValue - MathF.Round(y + (1.772F * cb), MidpointRounding.AwayFromZero)) * scaledK;
                 }
             }
-
-            public override void ConvertFromRgbInplace(in ComponentValues values) => throw new NotImplementedException();
         }
     }
 }

src/ImageSharp/Formats/Jpeg/Components/Decoder/ColorConverters/JpegColorConverter.FromYccKVector.cs

@@ -69,7 +69,7 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.Components.Decoder.ColorConverters
             }
 
             protected override void ConvertCoreInplaceToRgb(in ComponentValues values) =>
-                FromYccKScalar.ConvertCoreInplace(values, this.MaximumValue, this.HalfValue);
+                FromYccKScalar.ConvertToRgpInplace(values, this.MaximumValue, this.HalfValue);
 
             protected override void ConvertCoreVectorizedInplaceFromRgb(in ComponentValues values) => throw new System.NotImplementedException();
 

src/ImageSharp/Formats/Jpeg/Components/Encoder/JpegFrame.cs

@@ -11,7 +11,7 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.Components.Encoder
     /// </summary>
     internal sealed class JpegFrame : IDisposable
     {
-        public JpegFrame(Jpeg.JpegFrameConfig frameConfig, MemoryAllocator allocator, Image image, Decoder.JpegColorSpace colorSpace)
+        public JpegFrame(JpegFrameConfig frameConfig, MemoryAllocator allocator, Image image, Decoder.JpegColorSpace colorSpace)
         {
             this.ColorSpace = colorSpace;
 

src/ImageSharp/Formats/Jpeg/JpegColorType.cs

@@ -58,10 +58,5 @@ namespace SixLabors.ImageSharp.Formats.Jpeg
         /// CMYK colorspace (cyan, magenta, yellow, and key black) intended for printing.
         /// </summary>
         Cmyk = 7,
-
-        /// <summary>
-        /// YCCK colorspace.
-        /// </summary>
-        YccK = 8,
     }
 }

src/ImageSharp/Formats/Jpeg/JpegEncoder.cs

@@ -53,10 +53,9 @@ namespace SixLabors.ImageSharp.Formats.Jpeg
 
     public class JpegFrameConfig
     {
-        public JpegFrameConfig(JpegColorType colorType, int precision)
+        public JpegFrameConfig(JpegColorType colorType)
         {
             this.ColorType = colorType;
-            this.Precision = precision;
 
             int componentCount = GetComponentCountFromColorType(colorType);
             this.Components = new JpegComponentConfig[componentCount];
@@ -85,8 +84,6 @@ namespace SixLabors.ImageSharp.Formats.Jpeg
 
         public JpegColorType ColorType { get; }
 
-        public int Precision { get; }
-
         public JpegComponentConfig[] Components { get; }
 
         public JpegFrameConfig PopulateComponent(int index, byte id, int hsf, int vsf, int quantIndex, int dcIndex, int acIndex)

src/ImageSharp/Formats/Jpeg/JpegEncoderCore.cs

@@ -87,12 +87,9 @@ namespace SixLabors.ImageSharp.Formats.Jpeg
             ImageMetadata metadata = image.Metadata;
             JpegMetadata jpegMetadata = metadata.GetJpegMetadata();
 
-            // Compute number of components based on color type in options.
-            int componentCount = (this.colorType == JpegColorType.Luminance) ? 1 : 3;
-
             // TODO: Right now encoder writes both quantization tables for grayscale images - we shouldn't do that
             // Initialize the quantization tables.
-            this.InitQuantizationTables(componentCount, jpegMetadata, out Block8x8F luminanceQuantTable, out Block8x8F chrominanceQuantTable);
+            this.InitQuantizationTables(this.frameConfig.Components.Length, jpegMetadata, out Block8x8F luminanceQuantTable, out Block8x8F chrominanceQuantTable);
 
             // Write the Start Of Image marker.
             this.WriteStartOfImage();
@@ -116,13 +113,13 @@ namespace SixLabors.ImageSharp.Formats.Jpeg
             this.WriteDefineQuantizationTables(ref luminanceQuantTable, ref chrominanceQuantTable);
 
             // Write the image dimensions.
-            this.WriteStartOfFrame(image.Width, image.Height, this.frameConfig.Components);
+            this.WriteStartOfFrame(image.Width, image.Height, this.frameConfig);
 
             // Write the Huffman tables.
-            this.WriteDefineHuffmanTables(componentCount);
+            this.WriteDefineHuffmanTables(this.frameConfig.Components.Length);
 
             // Write the scan header.
-            this.WriteStartOfScan(componentCount, this.frameConfig.Components);
+            this.WriteStartOfScan(this.frameConfig.Components.Length, this.frameConfig.Components);
 
             var frame = new Components.Encoder.JpegFrame(this.frameConfig, Configuration.Default.MemoryAllocator, image, GetTargetColorSpace(this.frameConfig.ColorType));
             var quantTables = new Block8x8F[] { luminanceQuantTable, chrominanceQuantTable };
@@ -636,8 +633,10 @@ namespace SixLabors.ImageSharp.Formats.Jpeg
         /// <param name="height">The height of the image.</param>
         /// <param name="componentCount">The number of components in a pixel.</param>
         /// <param name="componentIds">The component Id's.</param>
-        private void WriteStartOfFrame(int width, int height, JpegComponentConfig[] components)
+        private void WriteStartOfFrame(int width, int height, JpegFrameConfig frame)
         {
+            JpegComponentConfig[] components = frame.Components;
+
             // Length (high byte, low byte), 8 + components * 3.
             int markerlen = 8 + (3 * components.Length);
             this.WriteMarkerHeader(JpegConstants.Markers.SOF0, markerlen);