From 4b534b040ee83d956f0fe6f82847c092ade57e46 Mon Sep 17 00:00:00 2001
From: AntonyCorbett <antony@corbetts.org.uk>
Date: Sat, 19 Oct 2019 15:39:49 +0100
Subject: [PATCH] Fix for images with bad dpi

---
 OnlyM.CoreSys/GraphicsUtils.cs        | 41 ++++++++++++++++++++++++++-
 OnlyM/Services/ImageDisplayManager.cs | 17 ++---------
 SolutionInfo.cs                       |  2 +-
 3 files changed, 43 insertions(+), 17 deletions(-)

diff --git a/OnlyM.CoreSys/GraphicsUtils.cs b/OnlyM.CoreSys/GraphicsUtils.cs
index e07719924..930f3c133 100644
--- a/OnlyM.CoreSys/GraphicsUtils.cs
+++ b/OnlyM.CoreSys/GraphicsUtils.cs
@@ -16,6 +16,7 @@
 
     public static class GraphicsUtils
     {
+        private const int MaxDpi = 1200;
         private static readonly object _tagLibLocker = new object();
 
         public static bool AutoRotateIfRequired(string itemFilePath)
@@ -101,7 +102,10 @@ public static BitmapSource Downsize(string imageFilePath, int maxImageWidth, int
             return Downsize(image, maxImageWidth, maxImageHeight);
         }
 
-        public static BitmapSource Downsize(BitmapSource image, int maxImageWidth, int maxImageHeight)
+        public static BitmapSource Downsize(
+            BitmapSource image, 
+            int maxImageWidth, 
+            int maxImageHeight)
         {
             var factorWidth = (double)maxImageWidth / image.PixelWidth;
             var factorHeight = (double)maxImageHeight / image.PixelHeight;
@@ -245,6 +249,13 @@ public static BitmapImage GetBitmapImageWithCacheOnLoad(string imageFile)
             bmp.CacheOption = BitmapCacheOption.OnLoad;
             bmp.EndInit();
 
+            if (IsBadDpi(bmp))
+            {
+                // NB - if the DpiX and DpiY metadata is bad then the bitmap can't be displayed
+                // correctly, so fix it here...
+                return FixBadDpi(imageFile);
+            }
+
             return bmp;
         }
 
@@ -450,5 +461,33 @@ private static bool ImageRequiresRotation(string imageFilePath)
 
             return false;
         }
+
+        private static bool IsBadDpi(BitmapImage bmp)
+        {
+            return bmp.DpiX > MaxDpi || bmp.DpiY > MaxDpi;
+        }
+
+        private static BitmapImage FixBadDpi(string imageFile)
+        {
+            using (var imageFactory = new ImageFactory())
+            {
+                using (MemoryStream outStream = new MemoryStream())
+                {
+                    imageFactory
+                        .Load(imageFile)
+                        .Resolution(96, 96)
+                        .Save(outStream);
+
+                    var bitmapImage = new BitmapImage();
+
+                    bitmapImage.BeginInit();
+                    bitmapImage.CacheOption = BitmapCacheOption.OnLoad;
+                    bitmapImage.StreamSource = outStream;
+                    bitmapImage.EndInit();
+
+                    return bitmapImage;
+                }
+            }
+        }
     }
 }
diff --git a/OnlyM/Services/ImageDisplayManager.cs b/OnlyM/Services/ImageDisplayManager.cs
index 1698ad2ac..03d16d333 100644
--- a/OnlyM/Services/ImageDisplayManager.cs
+++ b/OnlyM/Services/ImageDisplayManager.cs
@@ -10,13 +10,13 @@
     using System.Windows.Controls;
     using System.Windows.Media;
     using System.Windows.Media.Animation;
-    using System.Windows.Media.Imaging;
     using System.Windows.Threading;
     using GalaSoft.MvvmLight.Threading;
     using OnlyM.Core.Extensions;
     using OnlyM.Core.Models;
     using OnlyM.Core.Services.Options;
     using OnlyM.Core.Utils;
+    using OnlyM.CoreSys;
     using OnlyM.Models;
     using OnlyM.Services.ImagesCache;
     using OnlyM.Slides;
@@ -373,7 +373,7 @@ private void ShowImageInControl(string imageFile, Image imageCtrl, ImageFadeType
 
             var imageSrc = _optionsService.CacheImages
                 ? ImageCache.GetImage(imageFile)
-                : GetBitmapImageWithCacheOnLoad(imageFile);
+                : GraphicsUtils.GetBitmapImageWithCacheOnLoad(imageFile);
 
             if (!shouldFadeIn)
             {
@@ -414,19 +414,6 @@ private void ShowImageInControl(string imageFile, Image imageCtrl, ImageFadeType
             }
         }
 
-        private BitmapImage GetBitmapImageWithCacheOnLoad(string imageFile)
-        {
-            var bmp = new BitmapImage();
-
-            bmp.BeginInit();
-            bmp.CreateOptions = BitmapCreateOptions.IgnoreColorProfile;
-            bmp.UriSource = new Uri(imageFile);
-            bmp.CacheOption = BitmapCacheOption.OnLoad;
-            bmp.EndInit();
-
-            return bmp;
-        }
-
         private void InitFromSlideshowFile(string mediaItemFilePath)
         {
             var sf = new SlideFile(mediaItemFilePath);
diff --git a/SolutionInfo.cs b/SolutionInfo.cs
index cb8024840..11ae3b258 100644
--- a/SolutionInfo.cs
+++ b/SolutionInfo.cs
@@ -6,4 +6,4 @@
 [assembly: AssemblyTrademark("")]
 [assembly: AssemblyCulture("")]
 
-[assembly: AssemblyVersion("1.5.0.18")]
\ No newline at end of file
+[assembly: AssemblyVersion("1.5.0.19")]
\ No newline at end of file