From 57ab2c5dd2c3899e9a059d143a9389341e7c74e8 Mon Sep 17 00:00:00 2001
From: James Jackson-South <james_south@hotmail.com>
Date: Mon, 16 Jan 2017 13:26:26 +1100
Subject: [PATCH] Match Photoshop subsampling rules

---
 src/ImageSharp.Formats.Jpeg/JpegEncoder.cs | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/ImageSharp.Formats.Jpeg/JpegEncoder.cs b/src/ImageSharp.Formats.Jpeg/JpegEncoder.cs
index 18fd990080..a672949c35 100644
--- a/src/ImageSharp.Formats.Jpeg/JpegEncoder.cs
+++ b/src/ImageSharp.Formats.Jpeg/JpegEncoder.cs
@@ -71,7 +71,8 @@ namespace ImageSharp.Formats
             }
             else
             {
-                encode.Encode(image, stream, this.Quality, this.Quality >= 80 ? JpegSubsample.Ratio444 : JpegSubsample.Ratio420);
+                // Match Photoshop and use 4:2:0 SUpsampling at quality < 51%
+                encode.Encode(image, stream, this.Quality, this.Quality >= 51 ? JpegSubsample.Ratio444 : JpegSubsample.Ratio420);
             }
         }
     }