removed ExifIdCode from ExifConstants and ExifProfile, using ExifMarker defined in Jpeg ProfileResolver

src/ImageSharp/Formats/Jpeg/Components/Decoder/ProfileResolver.cs

@@ -32,7 +32,7 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.Components.Decoder
         public static readonly byte[] AdobeMarker = Encoding.UTF8.GetBytes("Adobe");
 
         /// <summary>
-        /// Returns a value indicating whether the passed bytes are a match to the profile identifer
+        /// Returns a value indicating whether the passed bytes are a match to the profile identifier
         /// </summary>
         /// <param name="bytesToCheck">The bytes to check</param>
         /// <param name="profileIdentifier">The profile identifier</param>

src/ImageSharp/MetaData/Profiles/Exif/ExifConstants.cs

@@ -5,15 +5,6 @@ namespace SixLabors.ImageSharp.MetaData.Profiles.Exif
 {
     internal static class ExifConstants
     {
-        public static readonly byte[] ExifIdCode = {
-            (byte)'E',
-            (byte)'x',
-            (byte)'i',
-            (byte)'f',
-            0x00,
-            0x00
-        };
-
         public static readonly byte[] LittleEndianByteOrderMarker = {
             (byte)'I',
             (byte)'I',

src/ImageSharp/MetaData/Profiles/Exif/ExifProfile.cs

@@ -5,6 +5,7 @@ using System;
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
+using SixLabors.ImageSharp.Formats.Jpeg.Components.Decoder;
 using SixLabors.ImageSharp.PixelFormats;
 using SixLabors.ImageSharp.Primitives;
 
@@ -15,11 +16,6 @@ namespace SixLabors.ImageSharp.MetaData.Profiles.Exif
     /// </summary>
     public sealed class ExifProfile
     {
-        /// <summary>
-        /// The EXIF ID code: ASCII "Exif" followed by two zeros.
-        /// </summary>
-        private static readonly byte[] ExifCode = { 69, 120, 105, 102, 0, 0 };
-
         /// <summary>
         /// The byte array to read the EXIF profile from.
         /// </summary>
@@ -239,7 +235,8 @@ namespace SixLabors.ImageSharp.MetaData.Profiles.Exif
         /// Converts this instance to a byte array.
         /// </summary>
         /// <param name="includeExifIdCode">Indicates, if the Exif ID code should be included.
-        /// This Exif ID code should not be included in case of PNG's. Defaults to true.</param>
+        /// The Exif Id Code is part of the JPEG APP1 segment. This Exif ID code should not be included in case of PNG's.
+        /// Defaults to true.</param>
         /// <returns>The <see cref="T:byte[]"/></returns>
         public byte[] ToByteArray(bool includeExifIdCode = true)
         {
@@ -275,10 +272,10 @@ namespace SixLabors.ImageSharp.MetaData.Profiles.Exif
                 return false;
             }
 
-            int exifLength = ExifCode.Length;
+            int exifLength = ProfileResolver.ExifMarker.Length;
-            for (int i = 0; i < ExifCode.Length; i++)
+            for (int i = 0; i < ProfileResolver.ExifMarker.Length; i++)
             {
-                if (exifBytes[i] != ExifCode[i])
+                if (exifBytes[i] != ProfileResolver.ExifMarker[i])
                 {
                     return false;
                 }

src/ImageSharp/MetaData/Profiles/Exif/ExifWriter.cs

@@ -5,6 +5,7 @@ using System;
 using System.Buffers.Binary;
 using System.Collections.Generic;
 using System.Text;
+using SixLabors.ImageSharp.Formats.Jpeg.Components.Decoder;
 using SixLabors.ImageSharp.Primitives;
 
 namespace SixLabors.ImageSharp.MetaData.Profiles.Exif
@@ -42,13 +43,14 @@ namespace SixLabors.ImageSharp.MetaData.Profiles.Exif
         /// Returns the EXIF data.
         /// </summary>
         /// <param name="includeExifIdCode">Indicates, if the Exif ID code should be included.
-        /// This Exif ID code should not be included in case of PNG's. Defaults to true.</param>
+        /// The Exif Id Code is part of the JPEG APP1 segment. This Exif ID code should not be included in case of PNG's.
+        /// Defaults to true.</param>
         /// <returns>
         /// The <see cref="T:byte[]"/>.
         /// </returns>
         public byte[] GetData(bool includeExifIdCode = true)
         {
-            uint startIndex = 6;
+            uint startIndex = (uint)ProfileResolver.ExifMarker.Length;
             uint length;
             int exifIndex = -1;
             int gpsIndex = -1;
@@ -86,19 +88,19 @@ namespace SixLabors.ImageSharp.MetaData.Profiles.Exif
 
             if (includeExifIdCode)
             {
-                // Exif Code (6 bytes) + byte order marker (4 bytes)
+                // Exif Id Code "Exif00" (6 bytes)
-                length += 10;
+                length += (uint)ProfileResolver.ExifMarker.Length;
             }
             else
             {
                 // special case for PNG eXIf Chunk:
-                // two bytes for the byte Order marker 'II', followed by the number 42 (0x2A) and a 0, making 4 bytes total
-                length += 4;
-
                 // if the Exif Code ("Exif00") is not included, the start index is 0 instead of 6
                 startIndex = 0;
             }
 
+            // two bytes for the byte Order marker 'II', followed by the number 42 (0x2A) and a 0, making 4 bytes total
+            length += (uint)ExifConstants.LittleEndianByteOrderMarker.Length;
+
             length += 4 + 2;
 
             byte[] result = new byte[length];
@@ -106,8 +108,8 @@ namespace SixLabors.ImageSharp.MetaData.Profiles.Exif
             int i = 0;
             if (includeExifIdCode)
             {
-                ExifConstants.ExifIdCode.AsSpan().CopyTo(result); // 0-5
+                ProfileResolver.ExifMarker.AsSpan().CopyTo(result); // 0-5
-                i += ExifConstants.ExifIdCode.Length;
+                i += ProfileResolver.ExifMarker.Length;
             }
 
             // the byte order marker for little-endian, followed by the number 42 and a 0