Merge commits.

CONTRIB.md

@@ -1,6 +1,6 @@
 # Contributors to ExifLibrary
 
-* Ozgur Ozcitak
-* Devedse
+* [oozcitak](https://github.com/oozcitak)
+* [Devedse](https://github.com/devedse)
   - Conversion to .Net Standard
-  - Automatic builds
+  - Automatic builds

ExifLibrary/ExifExtendedProperty.cs

@@ -148,7 +148,7 @@ public override ExifInterOperability Interoperability
 
     /// <summary>
     /// Represents the exif version as a 4 byte ASCII string. (EXIF Specification: UNDEFINED) 
-    /// Used for the ExifVersion, FlashpixVersion, InteroperabilityVersion and GPSVersionID fields.
+    /// Used for the ExifVersion, FlashpixVersion and InteroperabilityVersion fields.
     /// </summary>
     public class ExifVersion : ExifProperty
     {
@@ -189,6 +189,28 @@ public override ExifInterOperability Interoperability
         }
     }
 
+    /// <summary>
+    /// Represents a version as a 4 byte byte array. (Specification: int8u[4]) 
+    /// Used for the GPSVersionID field.
+    /// </summary>
+    public class VersionID : ExifByteArray
+    {
+        public VersionID(ExifTag tag, byte [] value)
+            : base(tag, value)
+        {
+        }
+
+        public override string ToString()
+        {
+            StringBuilder sb = new StringBuilder();
+            foreach (var b in Value)
+            {
+                sb.Append(b).Append('.');
+            }
+            return sb.ToString().TrimEnd('.');
+        }
+    }
+
     /// <summary>
     /// Represents the location and area of the subject (EXIF Specification: 2xSHORT)
     /// The coordinate values, width, and height are expressed in relation to the 

ExifLibrary/ExifPropertyFactory.cs

@@ -134,7 +134,7 @@ public static ExifProperty Get(ushort tag, ushort type, uint count, byte[] value
             else if (ifd == IFD.GPS)
             {
                 if (tag == 0) // GPSVersionID
-                    return new ExifVersion(ExifTag.GPSVersionID, ExifBitConverter.ToString(value));
+                    return new VersionID(ExifTag.GPSVersionID, value);
                 else if (tag == 1) // GPSLatitudeRef
                     return new ExifEnumProperty<GPSLatitudeRef>(ExifTag.GPSLatitudeRef, (GPSLatitudeRef)value[0]);
                 else if (tag == 2) // GPSLatitude

ExifLibrary/JPEGFile.cs

@@ -161,23 +161,7 @@ protected internal JPEGFile(Stream stream, Encoding encoding)
         /// </summary>
         public override void Crush()
         {
-            // Keep JFIF Tags
-            List<ExifProperty> jfifProperties = new List<ExifProperty>();
-            foreach (ExifProperty prop in Properties)
-            {
-                if (prop.IFD == IFD.JFIF)
-                {
-                    if (prop.Tag == ExifTag.JFIFXThumbnail)
-                        prop.Value = 0;
-                    if (prop.Tag == ExifTag.JFIFYThumbnail)
-                        prop.Value = 0;
-                    if (prop.Tag == ExifTag.JFIFThumbnail)
-                        prop.Value = new JFIFThumbnail(JFIFThumbnail.ImageFormat.JPEG, new byte[0]);
-                }
-            }
             Properties.Clear();
-            foreach (ExifProperty prop in jfifProperties)
-                Properties.Add(prop);
 
             // Remove metadata sections.
             // Keep the sections in this whitelist only:
@@ -187,14 +171,11 @@ public override void Crush()
             //   RST0 - RST7
             //   SOI, EOI
             //   DQT
-            //   DNL
-            //   DRI
-            //   DHP
-            //   EXP
-            Sections.RemoveAll((section) =>
-            {
-                return (section.Marker < JPEGMarker.SOF0 || section.Marker > JPEGMarker.EXP);
-            });
+            //	 DNL
+            //	 DRI
+            //	 DHP
+            //	 EXP
+            Sections.RemoveAll(section => section.Marker < JPEGMarker.SOF0 || section.Marker > JPEGMarker.EXP);
         }
 
         /// <summary>
@@ -653,27 +634,26 @@ private bool WriteExifApp1(bool preserveMakerNote)
             thumbSizeLocation = 0;
             thumbSizeValue = 0;
             // Write thumbnail tags if they are missing, remove otherwise
-            int indexf = -1;
-            int indexl = -1;
-            for (int i = 0; i < Properties.Count; i++)
+            ExifProperty thumbnailFormatProperty = null;
+            ExifProperty thumbnailLengthProperty = null;
+            foreach (var prop in Properties)
             {
-                ExifProperty prop = Properties[i];
-                if (prop.Tag == ExifTag.ThumbnailJPEGInterchangeFormat) indexf = i;
-                if (prop.Tag == ExifTag.ThumbnailJPEGInterchangeFormatLength) indexl = i;
-                if (indexf != -1 && indexl != -1) break;
+                if (prop.Tag == ExifTag.ThumbnailJPEGInterchangeFormat) thumbnailFormatProperty = prop;
+                if (prop.Tag == ExifTag.ThumbnailJPEGInterchangeFormatLength) thumbnailLengthProperty = prop;
+                if (thumbnailFormatProperty != null && thumbnailLengthProperty != null) break;
             }
             if (Thumbnail == null)
             {
-                if (indexf != -1)
-                    Properties.RemoveAt(indexf);
-                if (indexl != -1)
-                    Properties.RemoveAt(indexl);
+                if (thumbnailFormatProperty != null)
+                    Properties.Remove(thumbnailFormatProperty);
+                if (thumbnailLengthProperty != null)
+                    Properties.Remove(thumbnailLengthProperty);
             }
             else
             {
-                if (indexf == -1)
+                if (thumbnailFormatProperty == null)
                     Properties.Add(new ExifUInt(ExifTag.ThumbnailJPEGInterchangeFormat, 0));
-                if (indexl == -1)
+                if (thumbnailLengthProperty == null)
                     Properties.Add(new ExifUInt(ExifTag.ThumbnailJPEGInterchangeFormatLength, 0));
             }
 
@@ -725,7 +705,8 @@ private bool WriteExifApp1(bool preserveMakerNote)
 
             if (ifdzeroth.Count == 0 && ifdgps.Count == 0 && ifdinterop.Count == 0 && ifdfirst.Count == 0 && Thumbnail == null)
             {
-                // Nothing to write
+                // Nothing to write to App1 section
+                exifApp1.Header = new byte[0];
                 return false;
             }