Create JpegExifRemovePatcher.cs

ZeroLevel/Services/Drawing/JpegExifRemovePatcher.cs

@@ -0,0 +1,58 @@
+using System.IO;
+
+namespace ZeroLevel.Services.Drawing
+{
+    public class JpegExifRemovePatcher
+    {
+        public void Patch(string source, string target)
+        {
+            using (var from_stream = File.Open(source, FileMode.Open))
+            {
+                using (var to_stream = File.Create(target))
+                {
+                    PatchAwayExif(from_stream, to_stream);
+                }
+            }
+        }
+
+        public Stream PatchAwayExif(Stream inStream, Stream outStream)
+        {
+            byte[] jpegHeader = new byte[2];
+            jpegHeader[0] = (byte)inStream.ReadByte();
+            jpegHeader[1] = (byte)inStream.ReadByte();
+            if (jpegHeader[0] == 0xff && jpegHeader[1] == 0xd8) //check if it's a jpeg file
+            {
+                SkipAppHeaderSection(inStream);
+            }
+            outStream.WriteByte(0xff);
+            outStream.WriteByte(0xd8);
+            int readCount;
+            byte[] readBuffer = new byte[8192];
+            while ((readCount = inStream.Read(readBuffer, 0, readBuffer.Length)) > 0)
+                outStream.Write(readBuffer, 0, readCount);
+
+            return outStream;
+        }
+
+        private void SkipAppHeaderSection(Stream inStream)
+        {
+            byte[] header = new byte[2];
+            header[0] = (byte)inStream.ReadByte();
+            header[1] = (byte)inStream.ReadByte();
+            while (header[0] == 0xff && (header[1] >= 0xe0 && header[1] <= 0xef))
+            {
+                int exifLength = inStream.ReadByte();
+                exifLength = exifLength << 8;
+                exifLength |= inStream.ReadByte();
+
+                for (int i = 0; i < exifLength - 2; i++)
+                {
+                    inStream.ReadByte();
+                }
+                header[0] = (byte)inStream.ReadByte();
+                header[1] = (byte)inStream.ReadByte();
+            }
+            inStream.Position -= 2; //skip back two bytes
+        }
+    }
+}