Added ImageSharp-only jpeg encoding benchmark

Author: Dmitry Pentin

tests/ImageSharp.Benchmarks/Codecs/Jpeg/EncodeJpegFeatures.cs

@@ -0,0 +1,89 @@
+// Copyright (c) Six Labors.
+// Licensed under the Apache License, Version 2.0.
+
+using System.Collections.Generic;
+using System.IO;
+using BenchmarkDotNet.Attributes;
+using SixLabors.ImageSharp.Formats.Jpeg;
+using SixLabors.ImageSharp.PixelFormats;
+using SixLabors.ImageSharp.Tests;
+
+namespace SixLabors.ImageSharp.Benchmarks.Codecs.Jpeg
+{
+    /// <summary>
+    /// Benchmark for all available encoding features of the Jpeg file type.
+    /// </summary>
+    /// <remarks>
+    /// This benchmark does NOT compare ImageSharp to any other jpeg codecs.
+    /// </remarks>
+    public class EncodeJpegFeatures
+    {
+        // Big enough, 4:4:4 chroma sampling
+        // No metadata
+        private const string TestImage = TestImages.Jpeg.Baseline.Calliphora;
+
+        public static IEnumerable<JpegColorType> ColorSpaceValues =>
+            new[] { JpegColorType.Luminance, JpegColorType.Rgb, JpegColorType.YCbCrRatio420, JpegColorType.YCbCrRatio444 };
+
+        [Params(75, 90, 100)]
+        public int Quality;
+
+        [ParamsSource(nameof(ColorSpaceValues), Priority = -100)]
+        public JpegColorType TargetColorSpace;
+
+        private Image<Rgb24> bmpCore;
+        private JpegEncoder encoder;
+
+        private MemoryStream destinationStream;
+
+        [GlobalSetup]
+        public void Setup()
+        {
+            using FileStream imageBinaryStream = File.OpenRead(Path.Combine(TestEnvironment.InputImagesDirectoryFullPath, TestImage));
+            this.bmpCore = Image.Load<Rgb24>(imageBinaryStream);
+            this.encoder = new JpegEncoder { Quality = this.Quality, ColorType = this.TargetColorSpace };
+            this.destinationStream = new MemoryStream();
+        }
+
+        [GlobalCleanup]
+        public void Cleanup()
+        {
+            this.bmpCore.Dispose();
+            this.bmpCore = null;
+
+            this.destinationStream.Dispose();
+            this.destinationStream = null;
+        }
+
+        [Benchmark]
+        public void Benchmark()
+        {
+            this.bmpCore.SaveAsJpeg(this.destinationStream, this.encoder);
+            this.destinationStream.Seek(0, SeekOrigin.Begin);
+        }
+    }
+}
+
+/*
+BenchmarkDotNet=v0.13.0, OS=Windows 10.0.19044
+Intel Core i7-6700K CPU 4.00GHz (Skylake), 1 CPU, 8 logical and 4 physical cores
+.NET SDK=6.0.100-preview.3.21202.5
+  [Host]     : .NET Core 3.1.21 (CoreCLR 4.700.21.51404, CoreFX 4.700.21.51508), X64 RyuJIT
+  DefaultJob : .NET Core 3.1.21 (CoreCLR 4.700.21.51404, CoreFX 4.700.21.51508), X64 RyuJIT
+
+
+|    Method | TargetColorSpace | Quality |      Mean |     Error |    StdDev |
+|---------- |----------------- |-------- |----------:|----------:|----------:|
+| Benchmark |        Luminance |      75 |  7.055 ms | 0.1411 ms | 0.3297 ms |
+| Benchmark |              Rgb |      75 | 12.139 ms | 0.0645 ms | 0.0538 ms |
+| Benchmark |    YCbCrRatio420 |      75 |  6.463 ms | 0.0282 ms | 0.0235 ms |
+| Benchmark |    YCbCrRatio444 |      75 |  8.616 ms | 0.0422 ms | 0.0374 ms |
+| Benchmark |        Luminance |      90 |  7.011 ms | 0.0361 ms | 0.0301 ms |
+| Benchmark |              Rgb |      90 | 13.119 ms | 0.0947 ms | 0.0886 ms |
+| Benchmark |    YCbCrRatio420 |      90 |  6.786 ms | 0.0328 ms | 0.0274 ms |
+| Benchmark |    YCbCrRatio444 |      90 |  8.672 ms | 0.0772 ms | 0.0722 ms |
+| Benchmark |        Luminance |     100 |  9.554 ms | 0.1211 ms | 0.1012 ms |
+| Benchmark |              Rgb |     100 | 19.475 ms | 0.1080 ms | 0.0958 ms |
+| Benchmark |    YCbCrRatio420 |     100 | 10.146 ms | 0.0585 ms | 0.0519 ms |
+| Benchmark |    YCbCrRatio444 |     100 | 15.317 ms | 0.0709 ms | 0.0592 ms |
+*/