Fix WMF and EMF being converted to PNG In ExcelPicture

EPPlus/Drawing/ExcelPicture.cs

@@ -38,6 +38,7 @@
 using System.Drawing;
 using System.Drawing.Imaging;
 using System.Diagnostics;
+using System.Linq;
 using OfficeOpenXml.Utils;
 using OfficeOpenXml.Compatibility;
 
@@ -61,14 +62,15 @@ internal ExcelPicture(ExcelDrawings drawings, XmlNode node) :
                 Part = drawings.Part.Package.GetPart(UriPic);
                 FileInfo f = new FileInfo(UriPic.OriginalString);
                 ContentType = GetContentType(f.Extension);
-                _image = Image.FromStream(Part.GetStream());
 
-#if (Core)
-                byte[] iby = ImageCompat.GetImageAsByteArray(_image);
-#else
-                ImageConverter ic =new ImageConverter();
-                var iby=(byte[])ic.ConvertTo(_image, typeof(byte[]));
-#endif
+                //Re-traverse the stream to avoid Image.Save call which converts emf/wmf to png
+                var ms = Part.GetStream();
+                _image = Image.FromStream(ms);
+
+                var iby = new byte[ms.Length];
+                ms.Position = 0;
+                ms.Read(iby, 0, iby.Length);
+
                 var ii = _drawings._package.LoadImage(iby, UriPic, Part);
                 ImageHash = ii.Hash;
 
@@ -128,12 +130,10 @@ internal ExcelPicture(ExcelDrawings drawings, XmlNode node, FileInfo imageFile,
             var imagestream = new FileStream(imageFile.FullName, FileMode.Open, FileAccess.Read);
             _image = Image.FromStream(imagestream);
 
-#if (Core)
-            var img=ImageCompat.GetImageAsByteArray(_image);
-#else
-            ImageConverter ic = new ImageConverter();
-            var img = (byte[])ic.ConvertTo(_image, typeof(byte[]));
-#endif
+            //Re-traverse the stream to avoid Image.Save call which converts emf/wmf to png
+            var img = new byte[imagestream.Length];
+            imagestream.Position = 0;
+            imagestream.Read(img, 0, img.Length);
 
             imagestream.Close();
             UriPic = GetNewUri(package, "/xl/media/{0}" + imageFile.Name);

EPPlusTest/DrawingTest.cs

@@ -8,8 +8,8 @@
 using OfficeOpenXml.Drawing;
 using OfficeOpenXml.Drawing.Chart;
 using OfficeOpenXml.Style;
-using System.Diagnostics;
-using System.Reflection;
+using System.Drawing.Imaging;
+using System.IO.Compression;
 
 namespace EPPlusTest
 {
@@ -977,5 +977,87 @@ public void DrawingWidthAdjust()
             //    p.SaveAs(new FileInfo(@"c:\temp\colwidthAdjust.xlsx"));
             //}
         }
+
+        #region ImageFormat Test
+
+        [TestMethod]
+        public void AddPicture_Bmp_StoresFormat()
+        {
+            AddPicture_Assert("BitmapImage.bmp", ImageFormat.Bmp);
+        }
+
+        [TestMethod]
+        public void AddPicture_Gif_StoresFormat()
+        {
+            AddPicture_Assert("BitmapImage.gif", ImageFormat.Gif);
+        }
+
+        [TestMethod]
+        public void AddPicture_Png_StoresFormat()
+        {
+            AddPicture_Assert("BitmapImage.png", ImageFormat.Png);
+        }
+
+        [TestMethod]
+        public void AddPicture_Tif_StoresFormat()
+        {
+            AddPicture_Assert("BitmapImage.tif", ImageFormat.Tiff);
+        }
+
+        [TestMethod]
+        public void AddPicture_Jpg_StoresFormat()
+        {
+            AddPicture_Assert("Test1.jpg", ImageFormat.Jpeg);
+        }
+
+        [TestMethod]
+        public void AddPicture_Emf_StoresFormat()
+        {
+            AddPicture_Assert("Vector Drawing.emf", ImageFormat.Emf);
+        }
+
+        [TestMethod]
+        public void AddPicture_Wmf_StoresFormat()
+        {
+            AddPicture_Assert("Vector Drawing.wmf", ImageFormat.Wmf);
+        }
+
+        public void AddPicture_Assert(string fileName, ImageFormat format)
+        {
+            using (var pck = new ExcelPackage())
+            {
+                var workbook = pck.Workbook;
+                var ws = workbook.Worksheets.Add("Sheet1");
+
+                var pic = ws.Drawings.AddPicture("Pic4", new FileInfo(Path.Combine(_clipartPath, fileName)));
+                pic.From.Row = 0;
+                pic.From.Column = 0;
+
+                pic.To.Row = 30;
+                pic.To.Column = 23;
+
+                using (var zip = new ZipArchive(new MemoryStream(pck.GetAsByteArray()), ZipArchiveMode.Read))
+                {
+                    var found = false;
+
+                    foreach (var entry in zip.Entries)
+                    {
+                        if (entry.Name != $"1{fileName}")
+                            continue;
+
+                        found = true;
+                        var stream = entry.Open();
+                        var drawing = Image.FromStream(stream);
+
+                        Assert.AreEqual(format, drawing.RawFormat);
+                    }
+
+                    Assert.IsTrue(found, "Image was not found in zip.");
+                }
+            }
+
+        }
+
+        #endregion
     }
 }

EPPlusTest/EPPlusTest.csproj

@@ -85,6 +85,7 @@
     <Reference Include="System.Data" />
     <Reference Include="System.Design" />
     <Reference Include="System.Drawing" />
+    <Reference Include="System.IO.Compression" />
     <Reference Include="System.Security" />
     <Reference Include="System.Xml" />
     <Reference Include="WindowsBase">
@@ -272,7 +273,11 @@
     <EmbeddedResource Include="Resources\BitmapImage.gif" />
   </ItemGroup>
   <ItemGroup>
+    <EmbeddedResource Include="Resources\BitmapImage.bmp" />
+    <EmbeddedResource Include="Resources\BitmapImage.png" />
+    <EmbeddedResource Include="Resources\BitmapImage.tif" />
     <Content Include="Resources\Test1.jpg" />
+    <EmbeddedResource Include="Resources\Vector Drawing.emf" />
   </ItemGroup>
   <ItemGroup>
     <ProjectReference Include="..\EPPlus\EPPlus.csproj">

EPPlusTest/TestBase.cs

@@ -30,7 +30,7 @@ public void InitBase()
             var asm = Assembly.GetExecutingAssembly();
             var validExtensions = new[]
                 {
-                    ".gif", ".wmf"
+                    ".gif", ".wmf", ".jpg", "emf", "png", "tif", "bmp"
                 };
 
             foreach (var name in asm.GetManifestResourceNames())