Class PageIterator

Inheritance
System.Object
DisposableBase
PageIterator
ResultIterator
Implements
System.IDisposable
Inherited Members
Namespace: DynamicTesseract
Assembly: IronOcr.dll
Syntax
public class PageIterator : DisposableBase

Walking the layout of a recognized page, block by block down to individual symbols, runs through PageIterator. It moves a cursor over the regions Tesseract found and reports where each one sits, so code can map the structure of a page without decoding its text. When the text itself is needed too, ResultIterator derives from PageIterator and adds the recognized characters on top of the same traversal.

A PageIterator is obtained from a recognized page rather than constructed directly, and because it inherits DisposableBase it should be disposed (or wrapped in using) once the walk finishes. Begin resets the cursor to the first element, and the two Next overloads advance it, one stepping a single PageIteratorLevel and the other moving to the next element at one level while bounded by a parent level. IsAtBeginningOf and IsAtFinalOf test the cursor's position within the hierarchy so a loop knows where a block, paragraph, or line starts and ends.

At each stop, the iterator describes the current region. BlockType returns a PolyBlockType identifying the region's role, body text, heading, image, table, or separator, and TryGetBoundingBox fills a Rect with the region's pixel coordinates at a requested PageIteratorLevel, returning false when none is available. TryGetBaseline reports the text baseline the same way, and GetProperties reads font and size details for the current element. Pass the PageIteratorLevel that matches the granularity a task needs, from Block down to Symbol.

using DynamicTesseract;

void WalkBlocks(PageIterator iterator)
{
    iterator.Begin();
    do
    {
        if (iterator.TryGetBoundingBox(PageIteratorLevel.Block, out Rect box))
            Console.WriteLine($"{iterator.BlockType} at {box}");
    }
    while (iterator.Next(PageIteratorLevel.Block));
}

The OCR results how-to walks through reading recognized structure, the results objects example shows the result model, and the region of an image how-to covers working with page coordinates.

Fields

handle

Declaration
protected HandleRef handle
Field Value
Type Description
System.Runtime.InteropServices.HandleRef

page

Declaration
protected readonly Page page
Field Value
Type Description
Page

Properties

BlockType

Declaration
public PolyBlockType BlockType { get; }
Property Value
Type Description
PolyBlockType

Methods

Begin()

Declaration
public void Begin()

Dispose(Boolean)

Declaration
public override void Dispose(bool disposing)
Parameters
Type Name Description
System.Boolean disposing
Overrides

Finalize()

Declaration
protected override void Finalize()
Overrides

GetProperties()

Declaration
public ElementProperties GetProperties()
Returns
Type Description
ElementProperties

IsAtBeginningOf(PageIteratorLevel)

Declaration
public bool IsAtBeginningOf(PageIteratorLevel level)
Parameters
Type Name Description
PageIteratorLevel level
Returns
Type Description
System.Boolean

IsAtFinalOf(PageIteratorLevel, PageIteratorLevel)

Declaration
public bool IsAtFinalOf(PageIteratorLevel level, PageIteratorLevel element)
Parameters
Type Name Description
PageIteratorLevel level
PageIteratorLevel element
Returns
Type Description
System.Boolean

Next(PageIteratorLevel)

Declaration
public bool Next(PageIteratorLevel level)
Parameters
Type Name Description
PageIteratorLevel level
Returns
Type Description
System.Boolean

Next(PageIteratorLevel, PageIteratorLevel)

Declaration
public bool Next(PageIteratorLevel level, PageIteratorLevel element)
Parameters
Type Name Description
PageIteratorLevel level
PageIteratorLevel element
Returns
Type Description
System.Boolean

TryGetBaseline(PageIteratorLevel, out Rect)

Declaration
public bool TryGetBaseline(PageIteratorLevel level, out Rect bounds)
Parameters
Type Name Description
PageIteratorLevel level
Rect bounds
Returns
Type Description
System.Boolean

TryGetBoundingBox(PageIteratorLevel, out Rect)

Declaration
public bool TryGetBoundingBox(PageIteratorLevel level, out Rect bounds)
Parameters
Type Name Description
PageIteratorLevel level
Rect bounds
Returns
Type Description
System.Boolean

Implements

System.IDisposable

Inherited members

Dispose()
VerifyNotDisposed()
IsDisposed