#11 early access to the raw xobjects for images.

temporary 'safe' untested implementation of seac for type 1 charstrings.
make structure public
bump version of package and project to 0.0.3 (it had accidentally increased to 0.0.5)

src/UglyToad.PdfPig/XObjects/XObjectFactory.cs

@@ -0,0 +1,37 @@
+namespace UglyToad.PdfPig.XObjects
+{
+    using System;
+    using Graphics;
+    using Tokenization.Scanner;
+    using Tokens;
+
+    internal class XObjectFactory
+    {
+        public XObjectImage CreateImage(XObjectContentRecord xObject, IPdfTokenScanner pdfScanner, bool isLenientParsing)
+        {
+            if (xObject == null)
+            {
+                throw new ArgumentNullException(nameof(xObject));
+            }
+
+            if (xObject.Type != XObjectType.Image)
+            {
+                throw new InvalidOperationException($"Cannot create an image from an XObject with type: {xObject.Type}.");
+            }
+
+            var width = xObject.Stream.StreamDictionary.Get<NumericToken>(NameToken.Width, pdfScanner).Int;
+            var height = xObject.Stream.StreamDictionary.Get<NumericToken>(NameToken.Height, pdfScanner).Int;
+
+            var isJpxDecode = xObject.Stream.StreamDictionary.TryGet(NameToken.Filter, out var token) 
+                && token is NameToken filterName
+                && filterName.Equals(NameToken.JpxDecode);
+            
+            var isImageMask = xObject.Stream.StreamDictionary.TryGet(NameToken.ImageMask, out var maskToken)
+                              && maskToken is BooleanToken maskBoolean
+                              && maskBoolean.Data;
+
+            return new XObjectImage(width, height, isJpxDecode, isImageMask, xObject.Stream.StreamDictionary,
+                xObject.Stream.Data);
+        }
+    }
+}

src/UglyToad.PdfPig/XObjects/XObjectImage.cs

@@ -0,0 +1,67 @@
+namespace UglyToad.PdfPig.XObjects
+{
+    using System;
+    using System.Collections.Generic;
+    using Tokens;
+    using Util.JetBrains.Annotations;
+
+    /// <summary>
+    /// The raw stream from a PDF document representing an image XObject.
+    /// </summary>
+    public class XObjectImage
+    {
+        /// <summary>
+        /// The width of the image in samples.
+        /// </summary>
+        public int Width { get; }
+
+        /// <summary>
+        /// The height of the image in samples.
+        /// </summary>
+        public int Height { get; }
+
+        /// <summary>
+        /// The JPX filter encodes data using the JPEG2000 compression method.
+        /// A JPEG2000 data stream allows different versions of the image to be decoded
+        /// allowing for thumbnails to be extracted.
+        /// </summary>
+        public bool IsJpxEncoded { get; }
+
+        /// <summary>
+        /// Whether this image should be treated as an image maske.
+        /// </summary>
+        public bool IsImageMask { get; }
+
+        /// <summary>
+        /// The full dictionary for this Image XObject.
+        /// </summary>
+        [NotNull]
+        public DictionaryToken ImageDictionary { get; }
+
+        /// <summary>
+        /// The encoded bytes of this image, must be decoded via any
+        /// filters defined in the <see cref="ImageDictionary"/> prior to consumption.
+        /// </summary>
+        [NotNull]
+        public IReadOnlyList<byte> Bytes { get; }
+
+        /// <summary>
+        /// Creates a new <see cref="XObjectImage"/>.
+        /// </summary>
+        internal XObjectImage(int width, int height, bool isJpxEncoded, bool isImageMask, DictionaryToken imageDictionary, IReadOnlyList<byte> bytes)
+        {
+            Width = width;
+            Height = height;
+            IsJpxEncoded = isJpxEncoded;
+            IsImageMask = isImageMask;
+            ImageDictionary = imageDictionary ?? throw new ArgumentNullException(nameof(imageDictionary));
+            Bytes = bytes ?? throw new ArgumentNullException(nameof(bytes));
+        }
+
+        /// <inheritdoc />
+        public override string ToString()
+        {
+            return ImageDictionary.ToString();
+        }
+    }
+}

src/UglyToad.PdfPig/XObjects/XObjectType.cs

@@ -0,0 +1,9 @@
+namespace UglyToad.PdfPig.XObjects
+{
+    internal enum XObjectType
+    {
+        Image,
+        Form,
+        PostScript
+    }
+}