Implemented the IDecoderOptions inside the png decoder.

src/ImageSharp.Formats.Png/IPngDecoderOptions.cs

@@ -0,0 +1,20 @@
+// <copyright file="IPngDecoderOptions.cs" company="James Jackson-South">
+// Copyright (c) James Jackson-South and contributors.
+// Licensed under the Apache License, Version 2.0.
+// </copyright>
+
+namespace ImageSharp.Formats
+{
+    using System.Text;
+
+    /// <summary>
+    /// Encapsulates the png decoder options.
+    /// </summary>
+    public interface IPngDecoderOptions : IDecoderOptions
+    {
+        /// <summary>
+        /// Gets the encoding that should be used when reading text chunks.
+        /// </summary>
+        Encoding TextEncoding { get; }
+    }
+}

src/ImageSharp.Formats.Png/PngDecoder.cs

@@ -34,7 +34,9 @@ namespace ImageSharp.Formats
         public void Decode<TColor>(Image<TColor> image, Stream stream, IDecoderOptions options)
             where TColor : struct, IPixel<TColor>
         {
-            new PngDecoderCore().Decode(image, stream);
+            IPngDecoderOptions pngOptions = PngDecoderOptions.Create(options);
+
+            new PngDecoderCore(pngOptions).Decode(image, stream);
         }
     }
 }

src/ImageSharp.Formats.Png/PngDecoderCore.cs

@@ -64,6 +64,11 @@ namespace ImageSharp.Formats
         /// </summary>
         private readonly char[] chars = new char[4];
 
+        /// <summary>
+        /// The decoder options.
+        /// </summary>
+        private readonly IPngDecoderOptions options;
+
         /// <summary>
         /// Reusable crc for validating chunks.
         /// </summary>
@@ -120,6 +125,15 @@ namespace ImageSharp.Formats
             ColorTypes.Add((int)PngColorType.RgbWithAlpha, new byte[] { 8 });
         }
 
+        /// <summary>
+        /// Initializes a new instance of the <see cref="PngDecoderCore"/> class.
+        /// </summary>
+        /// <param name="options">The decoder options.</param>
+        public PngDecoderCore(IPngDecoderOptions options)
+        {
+            this.options = options ?? new PngDecoderOptions();
+        }
+
         /// <summary>
         /// Gets or sets the png color type
         /// </summary>
@@ -763,6 +777,11 @@ namespace ImageSharp.Formats
         private void ReadTextChunk<TColor>(Image<TColor> image, byte[] data, int length)
             where TColor : struct, IPixel<TColor>
         {
+            if (this.options.IgnoreMetadata)
+            {
+                return;
+            }
+
             int zeroIndex = 0;
 
             for (int i = 0; i < length; i++)
@@ -774,8 +793,8 @@ namespace ImageSharp.Formats
                 }
             }
 
-            string name = Encoding.Unicode.GetString(data, 0, zeroIndex);
+            string name = this.options.TextEncoding.GetString(data, 0, zeroIndex);
-            string value = Encoding.Unicode.GetString(data, zeroIndex + 1, length - zeroIndex - 1);
+            string value = this.options.TextEncoding.GetString(data, zeroIndex + 1, length - zeroIndex - 1);
 
             image.MetaData.Properties.Add(new ImageProperty(name, value));
         }

src/ImageSharp.Formats.Png/PngDecoderOptions.cs

@@ -0,0 +1,62 @@
+// <copyright file="PngDecoderOptions.cs" company="James Jackson-South">
+// Copyright (c) James Jackson-South and contributors.
+// Licensed under the Apache License, Version 2.0.
+// </copyright>
+
+namespace ImageSharp.Formats
+{
+    using System.Text;
+
+    /// <summary>
+    /// Encapsulates the png decoder options.
+    /// </summary>
+    public sealed class PngDecoderOptions : DecoderOptions, IPngDecoderOptions
+    {
+        private static readonly Encoding DefaultEncoding = Encoding.GetEncoding("ASCII");
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="PngDecoderOptions"/> class.
+        /// </summary>
+        public PngDecoderOptions()
+        {
+            this.InitializeWithDefaults();
+        }
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="PngDecoderOptions"/> class.
+        /// </summary>
+        /// <param name="options">The options for the decoder.</param>
+        private PngDecoderOptions(IDecoderOptions options)
+            : base(options)
+        {
+            this.InitializeWithDefaults();
+        }
+
+        /// <summary>
+        /// Gets or sets the encoding that should be used when reading text chunks.
+        /// </summary>
+        public Encoding TextEncoding { get; set; }
+
+        /// <summary>
+        /// Converts the options to a <see cref="IPngDecoderOptions"/> instance with a cast
+        /// or by creating a new instance with the specfied options.
+        /// </summary>
+        /// <param name="options">The options for the decoder.</param>
+        /// <returns>The options for the png decoder.</returns>
+        internal static IPngDecoderOptions Create(IDecoderOptions options)
+        {
+            IPngDecoderOptions pngOptions = options as IPngDecoderOptions;
+            if (pngOptions != null)
+            {
+                return pngOptions;
+            }
+
+            return new PngDecoderOptions(options);
+        }
+
+        private void InitializeWithDefaults()
+        {
+            this.TextEncoding = DefaultEncoding;
+        }
+    }
+}

tests/ImageSharp.Tests/Formats/Png/PngDecoderCoreTests.cs

@@ -0,0 +1,66 @@
+// <copyright file="JpegDecoderCoreTests.cs" company="James Jackson-South">
+// Copyright (c) James Jackson-South and contributors.
+// Licensed under the Apache License, Version 2.0.
+// </copyright>
+
+namespace ImageSharp.Tests
+{
+    using System.Text;
+    using Xunit;
+
+    using ImageSharp.Formats;
+
+    public class PngDecoderCoreTests
+    {
+        [Fact]
+        public void Decode_IgnoreMetadataIsFalse_TextChunckIsRead()
+        {
+            var options = new PngDecoderOptions()
+            {
+                IgnoreMetadata = false
+            };
+
+            TestFile testFile = TestFile.Create(TestImages.Png.Blur);
+
+            using (Image image = new Image(testFile.FilePath, options))
+            {
+                Assert.Equal(1, image.MetaData.Properties.Count);
+                Assert.Equal("Software", image.MetaData.Properties[0].Name);
+                Assert.Equal("paint.net 4.0.6", image.MetaData.Properties[0].Value);
+            }
+        }
+
+        [Fact]
+        public void Decode_IgnoreMetadataIsTrue_TextChunksAreIgnored()
+        {
+            var options = new PngDecoderOptions()
+            {
+                IgnoreMetadata = true
+            };
+
+            TestFile testFile = TestFile.Create(TestImages.Png.Blur);
+
+            using (Image image = new Image(testFile.FilePath, options))
+            {
+                Assert.Equal(0, image.MetaData.Properties.Count);
+            }
+        }
+
+        [Fact]
+        public void Decode_TextEncodingSetToUnicode_TextIsReadWithCorrectEncoding()
+        {
+            var options = new PngDecoderOptions()
+            {
+                TextEncoding = Encoding.Unicode
+            };
+
+            TestFile testFile = TestFile.Create(TestImages.Png.Blur);
+
+            using (Image image = new Image(testFile.FilePath, options))
+            {
+                Assert.Equal(1, image.MetaData.Properties.Count);
+                Assert.Equal("潓瑦慷敲", image.MetaData.Properties[0].Name);
+            }
+        }
+    }
+}