only call set resolution if we have positive x and y values

MediaBrowser.Controller/Drawing/ImageExtensions.cs

@@ -170,7 +170,7 @@ namespace MediaBrowser.Controller.Drawing
             var thumbnail = new Bitmap(croppedWidth, croppedHeight, PixelFormat.Format32bppPArgb);
 
             // Preserve the original resolution
-            thumbnail.SetResolution(bmp.HorizontalResolution, bmp.VerticalResolution);
+            TrySetResolution(thumbnail, bmp.HorizontalResolution, bmp.VerticalResolution);
 
             using (var thumbnailGraph = Graphics.FromImage(thumbnail))
             {
@@ -188,6 +188,20 @@ namespace MediaBrowser.Controller.Drawing
             return thumbnail;
         }
 
+        /// <summary>
+        /// Tries the set resolution.
+        /// </summary>
+        /// <param name="bmp">The BMP.</param>
+        /// <param name="x">The x.</param>
+        /// <param name="y">The y.</param>
+        private static void TrySetResolution(Bitmap bmp, float x, float y)
+        {
+            if (x > 0 && y > 0)
+            {
+                bmp.SetResolution(bmp.HorizontalResolution, bmp.VerticalResolution);
+            }
+        }
+
         /// <summary>
         /// Determines whether or not a row of pixels is all whitespace
         /// </summary>

MediaBrowser.Server.Implementations/Drawing/ImageProcessor.cs

@@ -229,7 +229,7 @@ namespace MediaBrowser.Server.Implementations.Drawing
                             using (var thumbnail = new Bitmap(newWidth, newHeight, PixelFormat.Format32bppPArgb))
                             {
                                 // Mono throw an exeception if assign 0 to SetResolution
-                                if (originalImage.HorizontalResolution >= 0 && originalImage.VerticalResolution >= 0)
+                                if (originalImage.HorizontalResolution > 0 && originalImage.VerticalResolution > 0)
                                 {
                                     // Preserve the original resolution
                                     thumbnail.SetResolution(originalImage.HorizontalResolution, originalImage.VerticalResolution);