/// <summary>
/// Get the blocks.
/// </summary>
/// <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>
public IReadOnlyList <TextBlock> GetBlocks(IEnumerable <Word> pageWords, decimal minimumWidth,
Func <IEnumerable <decimal>, decimal> dominantFontWidthFunc,
Func <IEnumerable <decimal>, decimal> dominantFontHeightFunc)
{
if (pageWords.Count() == 0)
{
return(EmptyArray <TextBlock> .Instance);
}
XYLeaf root = new XYLeaf(pageWords); // Create a root node.
XYNode node = VerticalCut(root, minimumWidth, dominantFontWidthFunc, dominantFontHeightFunc);
if (node.IsLeaf)
{
return(new List <TextBlock> {
new TextBlock((node as XYLeaf).GetLines())
});
}
else
{
var leafs = node.GetLeafs();
if (leafs.Count > 0)
{
return(leafs.Select(l => new TextBlock(l.GetLines())).ToList());
}
}
return(new List <TextBlock>());
}
/// <summary>
/// Get the blocks.
/// </summary>
/// <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>
public static XYNode GetBlocks(IEnumerable <Word> pageWords, decimal minimumWidth,
Func <IEnumerable <decimal>, decimal> dominantFontWidthFunc,
Func <IEnumerable <decimal>, decimal> dominantFontHeightFunc)
{
var root = new XYLeaf(pageWords); // Create a root node.
return(VerticalCut(root, minimumWidth, dominantFontWidthFunc, dominantFontHeightFunc));
}
private XYNode VerticalCut(XYLeaf leaf, decimal minimumWidth,
Func <IEnumerable <decimal>, decimal> dominantFontWidthFunc,
Func <IEnumerable <decimal>, decimal> dominantFontHeightFunc, int level = 0)
{
if (leaf.CountWords() <= 1 || leaf.BoundingBox.Width <= minimumWidth)
{
// we stop cutting if
// - only one word remains
// - width is too small
return(leaf);
}
// order words left to right
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)
.Select(x => Math.Abs(x.GlyphRectangle.Width)));
decimal domFontHeight = dominantFontHeightFunc(words.SelectMany(x => x.Letters)
.Select(x => Math.Abs(x.GlyphRectangle.Height)));
List <decimal[]> projectionProfile = new List <decimal[]>();
decimal[] currentProj = new decimal[2] {
words[0].BoundingBox.Left, words[0].BoundingBox.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]))
{
// it is overlapping
if (words[i].BoundingBox.Left >= currentProj[0] &&
words[i].BoundingBox.Left <= currentProj[1] &&
words[i].BoundingBox.Right > currentProj[1])
{
// |____|
// |____|
// |_______| <- updated
currentProj[1] = words[i].BoundingBox.Right;
}
// we ignore the following cases:
// |____|
// |____| (not possible because of OrderBy)
//
// |____|
//|___________| (not possible because of OrderBy)
//
// |____|
// |_|
}
else
{
// no overlap
if (words[i].BoundingBox.Left - currentProj[1] <= domFontWidth)
{
// if gap too small -> don't cut
// |____| |____|
currentProj[1] = words[i].BoundingBox.Right;
}
else if (currentProj[1] - currentProj[0] < minimumWidth)
{
// still too small
currentProj[1] = words[i].BoundingBox.Right;
}
else
{
// if gap big enough -> cut!
// |____| | |____|
if (i != wordsCount - 1) // will always add the last one after
{
projectionProfile.Add(currentProj);
currentProj = new decimal[2] {
words[i].BoundingBox.Left, words[i].BoundingBox.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 newNodes = newLeafs.Select(l => HorizontalCut(l, minimumWidth,
dominantFontWidthFunc, dominantFontHeightFunc, level)).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 XYLeaf(w)));
}
return(new XYNode(newNodes));
}
private XYNode HorizontalCut(XYLeaf leaf, decimal minimumWidth,
Func <IEnumerable <decimal>, decimal> dominantFontWidthFunc,
Func <IEnumerable <decimal>, decimal> dominantFontHeightFunc, int level = 0)
{
if (leaf.CountWords() <= 1)
{
// we stop cutting if
// - only one word remains
return(leaf);
}
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)
.Select(x => Math.Abs(x.GlyphRectangle.Width)));
decimal domFontHeight = dominantFontHeightFunc(words.SelectMany(x => x.Letters)
.Select(x => Math.Abs(x.GlyphRectangle.Height)));
List <decimal[]> projectionProfile = new List <decimal[]>();
decimal[] currentProj = new decimal[2] {
words[0].BoundingBox.Bottom, words[0].BoundingBox.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]))
{
// it is overlapping
if (words[i].BoundingBox.Bottom >= currentProj[0] &&
words[i].BoundingBox.Bottom <= currentProj[1] &&
words[i].BoundingBox.Top > currentProj[1])
{
currentProj[1] = words[i].BoundingBox.Top;
}
}
else
{
// no overlap
if (words[i].BoundingBox.Bottom - currentProj[1] <= domFontHeight)
{
// if gap too small -> don't cut
// |____| |____|
currentProj[1] = words[i].BoundingBox.Top;
}
else
{
// if gap big enough -> cut!
// |____| | |____|
if (i != wordsCount - 1) // will always add the last one after
{
projectionProfile.Add(currentProj);
currentProj = new decimal[2] {
words[i].BoundingBox.Bottom, words[i].BoundingBox.Top
};
}
}
}
if (i == wordsCount - 1)
{
projectionProfile.Add(currentProj);
}
}
if (projectionProfile.Count == 1)
{
if (level >= 1)
{
return(leaf);
}
else
{
level++;
}
}
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 = leaf.Words.Except(newLeafsEnums.SelectMany(x => x)).Where(x => !string.IsNullOrWhiteSpace(x.Text)).ToList();
if (lost.Count > 0)
{
newNodes.AddRange(lost.Select(w => new XYLeaf(w)));
}
return(new XYNode(newNodes));
}