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Fix stack overflow error in RecursiveXYCut

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Was linked to the new rotated rectangle methods
This commit is contained in:
BobLd
2020-02-10 13:53:59 +00:00
parent 6dfc7aea30
commit dd8baa0d2f
3 changed files with 66 additions and 40 deletions
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85
src/UglyToad.PdfPig.DocumentLayoutAnalysis/PageSegmenter/RecursiveXYCut.cs
View File

@@ -5,6 +5,7 @@
using System;
using System.Collections.Generic;
using System.Linq;
using UglyToad.PdfPig.Geometry;
/// <summary>
/// The recursive X-Y cut is a top-down page segmentation technique that decomposes a document
@@ -92,7 +93,7 @@
Func<IEnumerable<double>, double> dominantFontHeightFunc, int level = 0)
{
// order words left to right
var words = leaf.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.Normalise().Left).ToArray();
if (!words.Any())
{
@@ -112,29 +113,32 @@
return leaf;
}
// determine dominantFontWidth and dominantFontHeight
// determine dominantFontWidth
double domFontWidth = dominantFontWidthFunc(words.SelectMany(x => x.Letters)
.Select(x => Math.Abs(x.GlyphRectangle.Width)));
double domFontHeight = dominantFontHeightFunc(words.SelectMany(x => x.Letters)
.Select(x => Math.Abs(x.GlyphRectangle.Height)));
.Select(x => Math.Abs(x.GlyphRectangle.Normalise().Width)));
List<double[]> projectionProfile = new List<double[]>();
double[] currentProj = new double[2] { words[0].BoundingBox.Left, words[0].BoundingBox.Right };
var firstWordBound = words[0].BoundingBox.Normalise();
double[] currentProj = new double[2] { firstWordBound.Left, firstWordBound.Right };
int wordsCount = words.Count();
for (int i = 1; i < wordsCount; i++)
{
if ((words[i].BoundingBox.Left >= currentProj[0] && words[i].BoundingBox.Left <= currentProj[1])
|| (words[i].BoundingBox.Right >= currentProj[0] && words[i].BoundingBox.Right <= currentProj[1]))
var currentWordBound = words[i].BoundingBox.Normalise();
if ((currentWordBound.Left >= currentProj[0] && currentWordBound.Left <= currentProj[1])
|| (currentWordBound.Right >= currentProj[0] && currentWordBound.Right <= currentProj[1]))
{
// it is overlapping
if (words[i].BoundingBox.Left >= currentProj[0]
&& words[i].BoundingBox.Left <= currentProj[1]
&& words[i].BoundingBox.Right > currentProj[1])
if (currentWordBound.Left >= currentProj[0]
&& currentWordBound.Left <= currentProj[1]
&& currentWordBound.Right > currentProj[1])
{
// |____|
// |____|
// |_______| <- updated
currentProj[1] = words[i].BoundingBox.Right;
currentProj[1] = currentWordBound.Right;
}
// we ignore the following cases:
@@ -150,16 +154,16 @@
else
{
// no overlap
if (words[i].BoundingBox.Left - currentProj[1] <= domFontWidth)
if (currentWordBound.Left - currentProj[1] <= domFontWidth)
{
// if gap too small -> don't cut
// |____| |____|
currentProj[1] = words[i].BoundingBox.Right;
currentProj[1] = currentWordBound.Right;
}
else if (currentProj[1] - currentProj[0] < minimumWidth)
{
// still too small
currentProj[1] = words[i].BoundingBox.Right;
currentProj[1] = currentWordBound.Right;
}
else
{
@@ -168,16 +172,20 @@
if (i != wordsCount - 1) // will always add the last one after
{
projectionProfile.Add(currentProj);
currentProj = new double[2] { words[i].BoundingBox.Left, words[i].BoundingBox.Right };
currentProj = new double[2] { currentWordBound.Left, currentWordBound.Right };
}
}
}
if (i == wordsCount - 1) projectionProfile.Add(currentProj);
}
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 newLeafsEnums = projectionProfile.Select(p => leaf.Words.Where(w =>
{
var normalisedBB = w.BoundingBox.Normalise();
return normalisedBB.Left >= p[0] && normalisedBB.Right <= p[1];
}));
var newLeafs = newLeafsEnums.Where(e => e.Count() > 0).Select(e => new XYLeaf(e));
var newNodes = newLeafs.Select(l => HorizontalCut(l, minimumWidth,
dominantFontWidthFunc, dominantFontHeightFunc, level)).ToList();
@@ -194,7 +202,7 @@
Func<IEnumerable<double>, double> dominantFontWidthFunc,
Func<IEnumerable<double>, double> dominantFontHeightFunc, int level = 0)
{
var words = leaf.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.Normalise().Bottom).ToArray(); // order bottom to top
if (!words.Any())
{
@@ -211,36 +219,39 @@
return leaf;
}
// determine dominantFontWidth and dominantFontHeight
double domFontWidth = dominantFontWidthFunc(words.SelectMany(x => x.Letters)
.Select(x => Math.Abs(x.GlyphRectangle.Width)));
// determine dominantFontHeight
double domFontHeight = dominantFontHeightFunc(words.SelectMany(x => x.Letters)
.Select(x => Math.Abs(x.GlyphRectangle.Height)));
.Select(x => Math.Abs(x.GlyphRectangle.Normalise().Height)));
List<double[]> projectionProfile = new List<double[]>();
double[] currentProj = new double[2] { words[0].BoundingBox.Bottom, words[0].BoundingBox.Top };
var firstWordBound = words[0].BoundingBox.Normalise();
double[] currentProj = new double[2] { firstWordBound.Bottom, firstWordBound.Top };
int wordsCount = words.Count();
for (int i = 1; i < wordsCount; i++)
{
if ((words[i].BoundingBox.Bottom >= currentProj[0] && words[i].BoundingBox.Bottom <= currentProj[1])
|| (words[i].BoundingBox.Top >= currentProj[0] && words[i].BoundingBox.Top <= currentProj[1]))
var currentWordBound = words[i].BoundingBox.Normalise();
if ((currentWordBound.Bottom >= currentProj[0] && currentWordBound.Bottom <= currentProj[1])
|| (currentWordBound.Top >= currentProj[0] && currentWordBound.Top <= currentProj[1]))
{
// it is overlapping
if (words[i].BoundingBox.Bottom >= currentProj[0]
&& words[i].BoundingBox.Bottom <= currentProj[1]
&& words[i].BoundingBox.Top > currentProj[1])
if (currentWordBound.Bottom >= currentProj[0]
&& currentWordBound.Bottom <= currentProj[1]
&& currentWordBound.Top > currentProj[1])
{
currentProj[1] = words[i].BoundingBox.Top;
currentProj[1] = currentWordBound.Top;
}
}
else
{
// no overlap
if (words[i].BoundingBox.Bottom - currentProj[1] <= domFontHeight)
if (currentWordBound.Bottom - currentProj[1] <= domFontHeight)
{
// if gap too small -> don't cut
// |____| |____|
currentProj[1] = words[i].BoundingBox.Top;
currentProj[1] = currentWordBound.Top;
}
else
{
@@ -249,7 +260,7 @@
if (i != wordsCount - 1) // will always add the last one after
{
projectionProfile.Add(currentProj);
currentProj = new double[2] { words[i].BoundingBox.Bottom, words[i].BoundingBox.Top };
currentProj = new double[2] { currentWordBound.Bottom, currentWordBound.Top };
}
}
}
@@ -268,8 +279,12 @@
}
}
var newLeafsEnums = projectionProfile.Select(p =>
leaf.Words.Where(w => w.BoundingBox.Bottom >= p[0] && w.BoundingBox.Top <= p[1]));
var newLeafsEnums = projectionProfile.Select(p => leaf.Words.Where(w =>
{
var normalisedBB = w.BoundingBox.Normalise();
return normalisedBB.Bottom >= p[0] && normalisedBB.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();

9
src/UglyToad.PdfPig.DocumentLayoutAnalysis/PageSegmenter/XYLeaf.cs
View File

@@ -5,6 +5,7 @@
using System;
using System.Collections.Generic;
using System.Linq;
using UglyToad.PdfPig.Geometry;
/// <summary>
/// A Leaf node used in the <see cref="RecursiveXYCut"/> algorithm, i.e. a block.
@@ -63,11 +64,11 @@
throw new ArgumentException("XYLeaf(): The words contained in the leaf cannot be null.", nameof(words));
}
double left = words.Min(b => b.BoundingBox.Left);
double right = words.Max(b => b.BoundingBox.Right);
double left = words.Min(b => b.BoundingBox.Normalise().Left);
double right = words.Max(b => b.BoundingBox.Normalise().Right);
double bottom = words.Min(b => b.BoundingBox.Bottom);
double top = words.Max(b => b.BoundingBox.Top);
double bottom = words.Min(b => b.BoundingBox.Normalise().Bottom);
double top = words.Max(b => b.BoundingBox.Normalise().Top);
BoundingBox = new PdfRectangle(left, bottom, right, top);
Words = words.ToArray();

12
src/UglyToad.PdfPig/Geometry/GeometryExtensions.cs
View File

@@ -325,7 +325,7 @@
}
/// <summary>
/// Get the <see cref="PdfRectangle"/> that is the intersection of two rectangles.
/// Gets the <see cref="PdfRectangle"/> that is the intersection of two rectangles.
/// </summary>
public static PdfRectangle? Intersect(this PdfRectangle rectangle, PdfRectangle other)
{
@@ -335,6 +335,16 @@
Math.Min(rectangle.TopRight.X, other.TopRight.X),
Math.Min(rectangle.TopRight.Y, other.TopRight.Y));
}
/// <summary>
/// Gets the axis-aligned rectangle that completely containing the original rectangle, with no rotation.
/// </summary>
/// <param name="rectangle"></param>
public static PdfRectangle Normalise(this PdfRectangle rectangle)
{
var points = new[] { rectangle.BottomLeft, rectangle.BottomRight, rectangle.TopLeft, rectangle.TopRight };
return new PdfRectangle(points.Min(p => p.X), points.Min(p => p.Y), points.Max(p => p.X), points.Max(p => p.Y));
}
#endregion
#region PdfLine