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Merged
BobLd merged 1 commit into from
Feb 22, 2025
Merged

Resolve image data (implementation from @kasperdaff) #998

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205 changes: 124 additions & 81 deletions src/UglyToad.PdfPig/PdfExtensions.cs
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Original file line number Diff line number Diff line change
@@ -1,87 +1,130 @@
namespace UglyToad.PdfPig
namespace UglyToad.PdfPig
{
using System;
using System;
using System.Diagnostics.CodeAnalysis;
using Core;
using Filters;
using Core;
using Filters;
using Parser.Parts;
using Tokenization.Scanner;
using Tokens;

/// <summary>
/// Extensions for PDF types.
/// </summary>
public static class PdfExtensions
{
/// <summary>
/// Try and get the entry with a given name and type or look-up the object if it's an indirect reference.
/// </summary>
public static bool TryGet<T>(this DictionaryToken dictionary, NameToken name, IPdfTokenScanner tokenScanner, [NotNullWhen(true)] out T? token)
where T : class, IToken
{
token = default;
if (!dictionary.TryGet(name, out var t) || !(t is T typedToken))
{
if (t is IndirectReferenceToken reference)
{
return DirectObjectFinder.TryGet(reference, tokenScanner, out token);
}

return false;
}

token = typedToken;
return true;
}

/// <summary>
/// Get the entry with a given name and type or look-up the object if it's an indirect reference.
/// </summary>
public static T Get<T>(this DictionaryToken dictionary, NameToken name, IPdfTokenScanner scanner) where T : class, IToken
{
if (!dictionary.TryGet(name, out var token) || !(token is T typedToken))
{
if (!(token is IndirectReferenceToken indirectReference))
{
throw new PdfDocumentFormatException($"Dictionary does not contain token with name {name} of type {typeof(T).Name}.");
}

typedToken = DirectObjectFinder.Get<T>(indirectReference, scanner);
}

return typedToken;
using Tokenization.Scanner;
using Tokens;

/// <summary>
/// Extensions for PDF types.
/// </summary>
public static class PdfExtensions
{
/// <summary>
/// Try and get the entry with a given name and type or look-up the object if it's an indirect reference.
/// </summary>
public static bool TryGet<T>(this DictionaryToken dictionary, NameToken name, IPdfTokenScanner tokenScanner, [NotNullWhen(true)] out T? token)
where T : class, IToken
{
token = default;
if (!dictionary.TryGet(name, out var t) || !(t is T typedToken))
{
if (t is IndirectReferenceToken reference)
{
return DirectObjectFinder.TryGet(reference, tokenScanner, out token);
}

return false;
}

token = typedToken;
return true;
}

/// <summary>
/// Get the entry with a given name and type or look-up the object if it's an indirect reference.
/// </summary>
public static T Get<T>(this DictionaryToken dictionary, NameToken name, IPdfTokenScanner scanner) where T : class, IToken
{
if (!dictionary.TryGet(name, out var token) || !(token is T typedToken))
{
if (!(token is IndirectReferenceToken indirectReference))
{
throw new PdfDocumentFormatException($"Dictionary does not contain token with name {name} of type {typeof(T).Name}.");
}

typedToken = DirectObjectFinder.Get<T>(indirectReference, scanner);
}

return typedToken;
}

/// <summary>
/// Get the decoded data from this stream.
/// </summary>
public static ReadOnlyMemory<byte> Decode(this StreamToken stream, IFilterProvider filterProvider)
{
var filters = filterProvider.GetFilters(stream.StreamDictionary);

var transform = stream.Data;
for (var i = 0; i < filters.Count; i++)
{
transform = filters[i].Decode(transform.Span, stream.StreamDictionary, i);
}

return transform;
}

/// <summary>
/// Get the decoded data from this stream.
/// </summary>
public static ReadOnlyMemory<byte> Decode(this StreamToken stream, IFilterProvider filterProvider)
{
var filters = filterProvider.GetFilters(stream.StreamDictionary);

var transform = stream.Data;
for (var i = 0; i < filters.Count; i++)
{
transform = filters[i].Decode(transform.Span, stream.StreamDictionary, i);
}

return transform;
/// <summary>
/// Get the decoded data from this stream.
/// </summary>
public static ReadOnlyMemory<byte> Decode(this StreamToken stream, ILookupFilterProvider filterProvider, IPdfTokenScanner scanner)
{
var filters = filterProvider.GetFilters(stream.StreamDictionary, scanner);

var transform = stream.Data;
for (var i = 0; i < filters.Count; i++)
{
transform = filters[i].Decode(transform.Span, stream.StreamDictionary, i);
}

return transform;
}

/// <summary>
/// Returns an equivalent token where any indirect references of child objects are
/// recursively traversed and resolved.
/// </summary>
internal static T Resolve<T>(this T token, IPdfTokenScanner scanner) where T : IToken
{
return (T)ResolveInternal(token, scanner);
}

private static IToken ResolveInternal(this IToken token, IPdfTokenScanner scanner)
{
if (token is StreamToken stream)
{
return new StreamToken(Resolve(stream.StreamDictionary, scanner), stream.Data);
}

if (token is DictionaryToken dict)
{
var resolvedItems = new Dictionary<NameToken, IToken>();
foreach (var kvp in dict.Data)
{
var value = kvp.Value is IndirectReferenceToken reference ? scanner.Get(reference.Data).Data : kvp.Value;
resolvedItems[NameToken.Create(kvp.Key)] = ResolveInternal(value, scanner);
}

return new DictionaryToken(resolvedItems);
}

if (token is ArrayToken arr)
{
var resolvedItems = new List<IToken>();
for (int i = 0; i < arr.Length; i++)
{
var value = arr.Data[i] is IndirectReferenceToken reference ? scanner.Get(reference.Data).Data : arr.Data[i];
resolvedItems.Add(ResolveInternal(value, scanner));
}
return new ArrayToken(resolvedItems);
}

var val = token is IndirectReferenceToken tokenReference ? scanner.Get(tokenReference.Data).Data : token;
return val;
}

/// <summary>
/// Get the decoded data from this stream.
/// </summary>
public static ReadOnlyMemory<byte> Decode(this StreamToken stream, ILookupFilterProvider filterProvider, IPdfTokenScanner scanner)
{
var filters = filterProvider.GetFilters(stream.StreamDictionary, scanner);

var transform = stream.Data;
for (var i = 0; i < filters.Count; i++)
{
transform = filters[i].Decode(transform.Span, stream.StreamDictionary, i);
}

return transform;
}
}
}
}
}
73 changes: 18 additions & 55 deletions src/UglyToad.PdfPig/XObjects/XObjectFactory.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -34,24 +34,18 @@
if (xObject.Type != XObjectType.Image)
{
throw new InvalidOperationException($"Cannot create an image from an XObject with type: {xObject.Type}.");
}

var dictionary = xObject.Stream.StreamDictionary;
}
var dictionary = xObject.Stream.StreamDictionary.Resolve(pdfScanner);

var bounds = xObject.AppliedTransformation.Transform(new PdfRectangle(new PdfPoint(0, 0), new PdfPoint(1, 1)));

var width = dictionary.Get<NumericToken>(NameToken.Width, pdfScanner).Int;
var height = dictionary.Get<NumericToken>(NameToken.Height, pdfScanner).Int;
var width = dictionary.GetInt(NameToken.Width);
var height = dictionary.GetInt(NameToken.Height);

bool isImageMask = false;
if (dictionary.TryGet(NameToken.ImageMask, pdfScanner, out BooleanToken? isMaskToken))
{
dictionary = dictionary.With(NameToken.ImageMask, isMaskToken);
isImageMask = isMaskToken.Data;
}
var isImageMask = dictionary.TryGet(NameToken.ImageMask, out BooleanToken isMaskToken) && isMaskToken.Data;

var isJpxDecode = dictionary.TryGet(NameToken.Filter, pdfScanner, out NameToken filterName)
&& filterName.Equals(NameToken.JpxDecode);
var isJpxDecode = dictionary.TryGet(NameToken.Filter, out NameToken filterName) && filterName.Equals(NameToken.JpxDecode);

int bitsPerComponent;
if (isImageMask)
Expand All @@ -63,9 +57,9 @@
if (isJpxDecode)
{
// Optional for JPX
if (dictionary.TryGet(NameToken.BitsPerComponent, pdfScanner, out NumericToken? bitsPerComponentToken))
if (dictionary.TryGet(NameToken.BitsPerComponent, out NumericToken? bitsPerComponentToken))
{
bitsPerComponent = bitsPerComponentToken.Int;

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System.Diagnostics.Debug.Assert(bitsPerComponent == Jpeg2000Helper.GetJp2BitsPerComponent(xObject.Stream.Data.Span));
}
else
Expand All @@ -76,36 +70,24 @@
}
else
{
if (!dictionary.TryGet(NameToken.BitsPerComponent, pdfScanner, out NumericToken? bitsPerComponentToken))
if (!dictionary.TryGet(NameToken.BitsPerComponent, out NumericToken? bitsPerComponentToken))
{
throw new PdfDocumentFormatException($"No bits per component defined for image: {dictionary}.");
}

bitsPerComponent = bitsPerComponentToken.Int;

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}
}

var intent = xObject.DefaultRenderingIntent;
if (dictionary.TryGet(NameToken.Intent, pdfScanner, out NameToken renderingIntentToken))
if (dictionary.TryGet(NameToken.Intent, out NameToken renderingIntentToken))
{
intent = renderingIntentToken.Data.ToRenderingIntent();
}

var interpolate = dictionary.TryGet(NameToken.Interpolate, pdfScanner, out BooleanToken? interpolateToken)
&& interpolateToken.Data;

if (dictionary.TryGet(NameToken.Filter, out var filterToken) && filterToken is IndirectReferenceToken)
{
if (dictionary.TryGet(NameToken.Filter, pdfScanner, out ArrayToken? filterArray))
{
dictionary = dictionary.With(NameToken.Filter, filterArray);
}
else if (dictionary.TryGet(NameToken.Filter, pdfScanner, out NameToken? filterNameToken))
{
dictionary = dictionary.With(NameToken.Filter, filterNameToken);
}
}

var interpolate = dictionary.TryGet(NameToken.Interpolate, out BooleanToken? interpolateToken)
&& interpolateToken.Data;

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var supportsFilters = true;
var filters = filterProvider.GetFilters(dictionary, pdfScanner);
foreach (var filter in filters)
Expand All @@ -115,34 +97,15 @@
supportsFilters = false;
break;
}
}

var decodeParams = dictionary.GetObjectOrDefault(NameToken.DecodeParms, NameToken.Dp);
if (decodeParams is IndirectReferenceToken refToken)
{
dictionary = dictionary.With(NameToken.DecodeParms, pdfScanner.Get(refToken.Data).Data);
}

var jbig2GlobalsParams = dictionary.GetObjectOrDefault(NameToken.Jbig2Globals);
if (jbig2GlobalsParams is IndirectReferenceToken jbig2RefToken)
{
dictionary = dictionary.With(NameToken.Jbig2Globals, pdfScanner.Get(jbig2RefToken.Data).Data);
}

var imParams = dictionary.GetObjectOrDefault(NameToken.Im);
if (imParams is IndirectReferenceToken imRefToken)
{
dictionary = dictionary.With(NameToken.Im, pdfScanner.Get(imRefToken.Data).Data);
}

var streamToken = new StreamToken(dictionary, xObject.Stream.Data);

var decodedBytes = supportsFilters ? new Lazy<ReadOnlyMemory<byte>>(() => streamToken.Decode(filterProvider, pdfScanner))
: null;

var decode = Array.Empty<double>();

if (dictionary.TryGet(NameToken.Decode, pdfScanner, out ArrayToken? decodeArrayToken))
if (dictionary.TryGet(NameToken.Decode, out ArrayToken decodeArrayToken))
{
decode = decodeArrayToken.Data.OfType<NumericToken>()
.Select(x => x.Double)
Expand All @@ -152,19 +115,19 @@
ColorSpaceDetails? details = null;
if (!isImageMask)
{
if (dictionary.TryGet(NameToken.ColorSpace, pdfScanner, out NameToken? colorSpaceNameToken))
if (dictionary.TryGet(NameToken.ColorSpace, out NameToken? colorSpaceNameToken))
{
details = resourceStore.GetColorSpaceDetails(colorSpaceNameToken, dictionary);
}
else if (dictionary.TryGet(NameToken.ColorSpace, pdfScanner, out ArrayToken? colorSpaceArrayToken)
else if (dictionary.TryGet(NameToken.ColorSpace, out ArrayToken? colorSpaceArrayToken)
&& colorSpaceArrayToken.Length > 0 && colorSpaceArrayToken.Data[0] is NameToken firstColorSpaceName)

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{
details = resourceStore.GetColorSpaceDetails(firstColorSpaceName, dictionary);
}
else if (!isJpxDecode)
{
details = xObject.DefaultColorSpace;
}
}
}
else
{
Expand All @@ -184,7 +147,7 @@
dictionary,
xObject.Stream.Data,
decodedBytes,
details);
details);
}
}
}
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