#244 Update documentations

Author: IldarKhayrutdinov

src/ImageSharp/Formats/Png/PngEncoderCore.cs

@@ -85,32 +85,32 @@ internal sealed class PngEncoderCore : IDisposable
         private int height;
 
         /// <summary>
-        /// The previous scanline.
+        /// The raw data of previous scanline.
         /// </summary>
         private IManagedByteBuffer previousScanline;
 
         /// <summary>
-        /// The raw scanline.
+        /// The raw data of current scanline.
         /// </summary>
         private IManagedByteBuffer currentScanline;
 
         /// <summary>
-        /// The common buffer for the filters
+        /// The common buffer for the filters.
         /// </summary>
         private IManagedByteBuffer filterBuffer;
 
         /// <summary>
-        /// The buffer for the sub filter
+        /// The ext buffer for the sub filter, <see cref="PngFilterMethod.Adaptive"/>.
         /// </summary>
         private IManagedByteBuffer subFilter;
 
         /// <summary>
-        /// The buffer for the average filter
+        /// The ext buffer for the average filter, <see cref="PngFilterMethod.Adaptive"/>.
         /// </summary>
         private IManagedByteBuffer averageFilter;
 
         /// <summary>
-        /// The buffer for the Paeth filter
+        /// The ext buffer for the Paeth filter, <see cref="PngFilterMethod.Adaptive"/>.
         /// </summary>
         private IManagedByteBuffer paethFilter;
 
@@ -390,7 +390,7 @@ private void CollectPixelBytes<TPixel>(ReadOnlySpan<TPixel> rowSpan, IQuantizedF
         }
 
         /// <summary>
-        /// Apply filter for the pixel bytes.
+        /// Apply filter for the raw scanline.
         /// </summary>
         private IManagedByteBuffer FilterPixelBytes()
         {
@@ -780,9 +780,7 @@ private void AllocateExtBuffers()
                 int resultLength = this.filterBuffer.Length();
 
                 this.subFilter = this.memoryAllocator.AllocateManagedByteBuffer(resultLength, AllocationOptions.Clean);
-
                 this.averageFilter = this.memoryAllocator.AllocateManagedByteBuffer(resultLength, AllocationOptions.Clean);
-
                 this.paethFilter = this.memoryAllocator.AllocateManagedByteBuffer(resultLength, AllocationOptions.Clean);
             }
         }

src/ImageSharp/Formats/Png/PngEncoderHelpers.cs

@@ -7,6 +7,9 @@
 
 namespace SixLabors.ImageSharp.Formats.Png
 {
+    /// <summary>
+    /// The helper methods for <see cref="PngEncoderCore"/> class.
+    /// </summary>
     internal static class PngEncoderHelpers
     {
         /// <summary>

src/ImageSharp/Formats/Png/PngEncoderOptions.cs

@@ -6,7 +6,7 @@
 namespace SixLabors.ImageSharp.Formats.Png
 {
     /// <summary>
-    /// The <see cref="PngEncoderCore"/> options class.
+    /// The options structure for the <see cref="PngEncoderCore"/>.
     /// </summary>
     /// <seealso cref="SixLabors.ImageSharp.Formats.Png.IPngEncoderOptions" />
     internal class PngEncoderOptions : IPngEncoderOptions

src/ImageSharp/Formats/Png/PngEncoderOptionsHelpers.cs

@@ -9,7 +9,7 @@
 namespace SixLabors.ImageSharp.Formats.Png
 {
     /// <summary>
-    /// The PNG encoder options helper methods class.
+    /// The helper methods for the PNG encoder options.
     /// </summary>
     internal static class PngEncoderOptionsHelpers
     {

tests/ImageSharp.Tests/Formats/Png/PngEncoderTests.cs

@@ -2,7 +2,6 @@
 // Licensed under the Apache License, Version 2.0.
 
 // ReSharper disable InconsistentNaming
-using System.Diagnostics;
 using System.IO;
 using System.Linq;
 
@@ -134,7 +133,7 @@ public void WorksWithAllFilterMethods<TPixel>(TestImageProvider<TPixel> provider
             where TPixel : struct, IPixel<TPixel>
         {
             foreach (PngInterlaceMode interlaceMode in InterlaceMode)
-            { 
+            {
                 TestPngEncoderCore(
                 provider,
                 PngColorType.RgbWithAlpha,