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Update with corrections

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This commit is contained in:
BobLd
2019-06-18 20:48:49 +01:00
parent 4416793f6d
commit f8d0883da5
5 changed files with 126 additions and 96 deletions
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119
src/UglyToad.PdfPig/DocumentLayoutAnalysis/RecursiveXYCut.cs
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@@ -10,14 +10,14 @@ namespace UglyToad.PdfPig.DocumentLayoutAnalysis
/// The recursive X-Y cut is a top-down page segmentation technique that decomposes a document
/// recursively into a set of rectangular blocks. This implementation leverages bounding boxes.
/// https://en.wikipedia.org/wiki/Recursive_X-Y_cut
/// <para>See 'Recursive X-Y Cut using Bounding Boxes of Connected Components' by Jaekyu Ha and Robert M.Haralick Ihsin T. Phillips</para>
/// <para>See 'Recursive X-Y Cut using Bounding Boxes of Connected Components' by Jaekyu Ha, Robert M.Haralick and Ihsin T. Phillips</para>
/// </summary>
public class RecursiveXYCut
{
/// <summary>
/// Get the blocks.
/// </summary>
/// <param name="pageWords">The words in a page.</param>
/// <param name="pageWords">The words in the page.</param>
/// <param name="minimumWidth">The minimum width for a block.</param>
/// <param name="dominantFontWidth">The dominant font width.</param>
/// <param name="dominantFontHeight">The dominant font height.</param>
@@ -31,7 +31,7 @@ namespace UglyToad.PdfPig.DocumentLayoutAnalysis
/// <summary>
/// Get the blocks.
/// </summary>
/// <param name="pageWords">The words in a page.</param>
/// <param name="pageWords">The words in the page.</param>
/// <param name="minimumWidth">The minimum width for a block.</param>
/// <param name="dominantFontWidthFunc">The function that determines the dominant font width.</param>
/// <param name="dominantFontHeightFunc">The function that determines the dominant font height.</param>
@@ -40,24 +40,24 @@ namespace UglyToad.PdfPig.DocumentLayoutAnalysis
Func<IEnumerable<decimal>, decimal> dominantFontWidthFunc,
Func<IEnumerable<decimal>, decimal> dominantFontHeightFunc)
{
var root = new XYLeef(pageWords);
var root = new XYLeaf(pageWords);
return VerticalCut(root, minimumWidth, dominantFontWidthFunc, dominantFontHeightFunc);
}
private static XYNode VerticalCut(XYLeef leef, decimal minimumWidth,
private static XYNode VerticalCut(XYLeaf leaf, decimal minimumWidth,
Func<IEnumerable<decimal>, decimal> dominantFontWidthFunc,
Func<IEnumerable<decimal>, decimal> dominantFontHeightFunc, int level = 0)
{
if (leef.CountWords() <= 1 || leef.BoundingBox.Width <= minimumWidth)
if (leaf.CountWords() <= 1 || leaf.BoundingBox.Width <= minimumWidth)
{
// we stop cutting if
// - only one word remains
// - width is too small
return leef;
return leaf;
}
// order words left to right
var words = leef.Words.Where(w => !string.IsNullOrWhiteSpace(w.Text)).OrderBy(w => w.BoundingBox.Left).ToArray();
var words = leaf.Words.Where(w => !string.IsNullOrWhiteSpace(w.Text)).OrderBy(w => w.BoundingBox.Left).ToArray();
// determine dominantFontWidth and dominantFontHeight
decimal domFontWidth = dominantFontWidthFunc(words.SelectMany(x => x.Letters)
@@ -122,33 +122,33 @@ namespace UglyToad.PdfPig.DocumentLayoutAnalysis
if (i == wordsCount - 1) projectionProfile.Add(currentProj);
}
var newLeefsEnums = projectionProfile.Select(p => leef.Words.Where(w => w.BoundingBox.Left >= p[0] && w.BoundingBox.Right <= p[1]));
var newLeefs = newLeefsEnums.Where(e => e.Count() > 0).Select(e => new XYLeef(e));
var newLeafsEnums = projectionProfile.Select(p => leaf.Words.Where(w => w.BoundingBox.Left >= p[0] && w.BoundingBox.Right <= p[1]));
var newLeafs = newLeafsEnums.Where(e => e.Count() > 0).Select(e => new XYLeaf(e));
var newNodes = newLeefs.Select(l => HorizontalCut(l, minimumWidth,
var newNodes = newLeafs.Select(l => HorizontalCut(l, minimumWidth,
dominantFontWidthFunc, dominantFontHeightFunc, level)).ToList();
var lost = leef.Words.Except(newLeefsEnums.SelectMany(x => x)).Where(x => !string.IsNullOrWhiteSpace(x.Text)).ToList();
var lost = leaf.Words.Except(newLeafsEnums.SelectMany(x => x)).Where(x => !string.IsNullOrWhiteSpace(x.Text)).ToList();
if (lost.Count > 0)
{
newNodes.AddRange(lost.Select(w => new XYLeef(w)));
newNodes.AddRange(lost.Select(w => new XYLeaf(w)));
}
return new XYNode(newNodes);
}
private static XYNode HorizontalCut(XYLeef leef, decimal minimumWidth,
private static XYNode HorizontalCut(XYLeaf leaf, decimal minimumWidth,
Func<IEnumerable<decimal>, decimal> dominantFontWidthFunc,
Func<IEnumerable<decimal>, decimal> dominantFontHeightFunc, int level = 0)
{
if (leef.CountWords() <= 1)
if (leaf.CountWords() <= 1)
{
// we stop cutting if
// - only one word remains
return leef;
return leaf;
}
var words = leef.Words.Where(w => !string.IsNullOrWhiteSpace(w.Text)).OrderBy(w => w.BoundingBox.Bottom).ToArray(); // order bottom to top
var words = leaf.Words.Where(w => !string.IsNullOrWhiteSpace(w.Text)).OrderBy(w => w.BoundingBox.Bottom).ToArray(); // order bottom to top
// determine dominantFontWidth and dominantFontHeight
decimal domFontWidth = dominantFontWidthFunc(words.SelectMany(x => x.Letters)
@@ -199,7 +199,7 @@ namespace UglyToad.PdfPig.DocumentLayoutAnalysis
{
if (level >= 1)
{
return leef;
return leaf;
}
else
{
@@ -207,16 +207,16 @@ namespace UglyToad.PdfPig.DocumentLayoutAnalysis
}
}
var newLeefsEnums = projectionProfile.Select(p =>
leef.Words.Where(w => w.BoundingBox.Bottom >= p[0] && w.BoundingBox.Top <= p[1]));
var newLeefs = newLeefsEnums.Where(e => e.Count() > 0).Select(e => new XYLeef(e));
var newNodes = newLeefs.Select(l => VerticalCut(l, minimumWidth,
var newLeafsEnums = projectionProfile.Select(p =>
leaf.Words.Where(w => w.BoundingBox.Bottom >= p[0] && w.BoundingBox.Top <= p[1]));
var newLeafs = newLeafsEnums.Where(e => e.Count() > 0).Select(e => new XYLeaf(e));
var newNodes = newLeafs.Select(l => VerticalCut(l, minimumWidth,
dominantFontWidthFunc, dominantFontHeightFunc, level)).ToList();
var lost = leef.Words.Except(newLeefsEnums.SelectMany(x => x)).Where(x => !string.IsNullOrWhiteSpace(x.Text)).ToList();
var lost = leaf.Words.Except(newLeafsEnums.SelectMany(x => x)).Where(x => !string.IsNullOrWhiteSpace(x.Text)).ToList();
if (lost.Count > 0)
{
newNodes.AddRange(lost.Select(w => new XYLeef(w)));
newNodes.AddRange(lost.Select(w => new XYLeaf(w)));
}
return new XYNode(newNodes);
}
@@ -228,9 +228,9 @@ namespace UglyToad.PdfPig.DocumentLayoutAnalysis
public class XYNode
{
/// <summary>
/// Returns true if this node is a leef, false otherwise.
/// Returns true if this node is a leaf, false otherwise.
/// </summary>
public virtual bool IsLeef => false;
public virtual bool IsLeaf => false;
/// <summary>
/// The rectangle completely containing the node.
@@ -255,16 +255,16 @@ namespace UglyToad.PdfPig.DocumentLayoutAnalysis
}
/// <summary>
/// Recursively gets the leefs (last nodes) of this node.
/// Recursively gets the leafs (last nodes) of this node.
/// </summary>
/// <returns></returns>
public virtual List<XYLeef> GetLeefs()
public virtual List<XYLeaf> GetLeafs()
{
List<XYLeef> leefs = new List<XYLeef>();
if (Children == null || Children.Count() == 0) return leefs;
List<XYLeaf> leafs = new List<XYLeaf>();
if (Children == null || Children.Count() == 0) return leafs;
int level = 0;
RecursiveGetLeefs(Children, ref leefs, level);
return leefs;
RecursiveGetLeafs(Children, ref leafs, level);
return leafs;
}
/// <summary>
@@ -297,86 +297,83 @@ namespace UglyToad.PdfPig.DocumentLayoutAnalysis
private void RecursiveCount(IEnumerable<XYNode> children, ref int count)
{
if (children.Count() == 0) return;
foreach (XYNode node in children.Where(x => x.IsLeef))
foreach (XYNode node in children.Where(x => x.IsLeaf))
{
count += node.CountWords();
}
foreach (XYNode node in children.Where(x => !x.IsLeef))
foreach (XYNode node in children.Where(x => !x.IsLeaf))
{
RecursiveCount(node.Children, ref count);
}
}
private void RecursiveGetLeefs(IEnumerable<XYNode> children, ref List<XYLeef> leefs, int level)
private void RecursiveGetLeafs(IEnumerable<XYNode> children, ref List<XYLeaf> leafs, int level)
{
if (children.Count() == 0) return;
bool isVerticalCut = level % 2 == 0;
foreach (XYLeef node in children.Where(x => x.IsLeef))
foreach (XYLeaf node in children.Where(x => x.IsLeaf))
{
leefs.Add(node);
leafs.Add(node);
}
level++;
IEnumerable<XYNode> notLeefs = children.Where(x => !x.IsLeef);
IEnumerable<XYNode> notLeafs = children.Where(x => !x.IsLeaf);
if (isVerticalCut)
{
notLeefs = notLeefs.OrderBy(x => x.BoundingBox.Left).ToList();
notLeafs = notLeafs.OrderBy(x => x.BoundingBox.Left).ToList();
}
else
{
notLeefs = notLeefs.OrderByDescending(x => x.BoundingBox.Top).ToList();
notLeafs = notLeafs.OrderByDescending(x => x.BoundingBox.Top).ToList();
}
foreach (XYNode node in notLeefs)
foreach (XYNode node in notLeafs)
{
RecursiveGetLeefs(node.Children, ref leefs, level);
RecursiveGetLeafs(node.Children, ref leafs, level);
}
}
public override string ToString()
{
return (IsLeef ? "Leef" : "Node");
return (IsLeaf ? "Leaf" : "Node");
}
}
/// <summary>
/// A Leef node used in the <see cref="RecursiveXYCut"/> algorithm, i.e. a block.
/// A Leaf node used in the <see cref="RecursiveXYCut"/> algorithm, i.e. a block.
/// </summary>
public class XYLeef : XYNode
public class XYLeaf : XYNode
{
/// <summary>
/// Returns true if this node is a leef, false otherwise.
/// Returns true if this node is a leaf, false otherwise.
/// </summary>
public override bool IsLeef => true;
public override bool IsLeaf => true;
/// <summary>
/// The words in the leef.
/// The words in the leaf.
/// </summary>
public Word[] Words { get; set; }
/// <summary>
/// The number of words in the leef.
/// The number of words in the leaf.
/// </summary>
/// <returns></returns>
public override int CountWords() => Words == null ? 0 : Words.Length;
/// <summary>
/// Returns null as a leef doesn't have leefs.
/// Returns null as a leaf doesn't have leafs.
/// </summary>
/// <returns></returns>
public override List<XYLeef> GetLeefs()
public override List<XYLeaf> GetLeafs()
{
return null;
}
/// <summary>
/// Gets the lines of the leef.
/// Gets the lines of the leaf.
/// </summary>
/// <returns></returns>
public TextLine[] GetLines()
{
var groupedWords = Words.GroupBy(x => x.BoundingBox.Bottom).ToDictionary(x => x.Key, x => x.ToList());
@@ -384,19 +381,19 @@ namespace UglyToad.PdfPig.DocumentLayoutAnalysis
}
/// <summary>
/// Create a new <see cref="XYLeef"/>.
/// Create a new <see cref="XYLeaf"/>.
/// </summary>
/// <param name="words">The words contained in the leef.</param>
public XYLeef(params Word[] words) : this(words == null ? null : words.ToList())
/// <param name="words">The words contained in the leaf.</param>
public XYLeaf(params Word[] words) : this(words == null ? null : words.ToList())
{
}
/// <summary>
/// Create a new <see cref="XYLeef"/>.
/// Create a new <see cref="XYLeaf"/>.
/// </summary>
/// <param name="words">The words contained in the leef.</param>
public XYLeef(IEnumerable<Word> words) : base(null)
/// <param name="words">The words contained in the leaf.</param>
public XYLeaf(IEnumerable<Word> words) : base(null)
{
decimal left = words.Min(b => b.BoundingBox.Left);
decimal right = words.Max(b => b.BoundingBox.Right);