Class OcrInputPage

A full page (one image) within an OcrInput object.

Inheritance

System.Object

OcrInputPage

OcrInput.Page

Namespace: IronOcr

Assembly: IronOcr.dll

Syntax

public class OcrInputPage : Object

OcrInputPage is one page, a single image, inside an OcrInput. A developer reaches for it to inspect or adjust an individual page after loading, rather than treating the whole input as one block: read a page's dimensions, restrict the read to a region, or export the page back out as an image. The pages of an input are enumerated by OcrInputBase.GetPages, which returns one OcrInputPage per loaded image.

The geometry properties describe the page as loaded. Width and Height give its pixel size, HorizontalDPI and VerticalDPI its resolution, and Index its position in the input. ContentArea is the one settable property: assign a Rectangle to limit recognition to part of the page, the building block behind region-of-interest reads. The methods cover two jobs. Region discovery is handled by FindTextRegion, which returns the bounding rectangle of the text on the page, and GetTextRegions, which returns a list of regions for a page with several text blocks. Image export is handled by ToBitmap, which returns the page as an AnyBitmap, SaveAsImage, which writes it to a file, GetCropRectangleImage, which returns just the ContentArea, and DrawRectanglesOnPage, which renders rectangles onto the page for debugging.

Set ContentArea to read only the part of a page that matters, or call FindTextRegion first to let IronOCR locate the text, then read the input as usual. Do not confuse OcrInputPage with OcrInput.Page, the nested type that extends it.

The region of an image how-to reads a content area, and the input images how-to loads the pages.

using var input = new OcrInput();
input.LoadImage("page.png");
OcrInputPage page = input.GetPages().First();
page.ContentArea = new Rectangle(0, 0, 600, 200);

Properties

ContentArea

Crop area of this page. If not null, text will only be read from within the ContentArea rectangle.

Declaration

public Rectangle ContentArea { get; set; }

Property Value

Type	Description
IronSoftware.Drawing.Rectangle

Height

Height in Pixels

Declaration

public int Height { get; }

Property Value

Type	Description
System.Int32

HorizontalDPI

Resolution in DPI on X axis

Declaration

public int HorizontalDPI { get; }

Property Value

Type	Description
System.Int32

Index

Zero based page number

Declaration

public int Index { get; }

Property Value

Type	Description
System.Int32

VerticalDPI

Resolution in DPI on Y axis

Declaration

public int VerticalDPI { get; }

Property Value

Type	Description
System.Int32

Width

Width in Pixels

Declaration

public int Width { get; }

Property Value

Type	Description
System.Int32

Methods

DrawRectanglesOnPage(Rectangle[], Color)

Draw many Rectangles on a OcrInputPage.

Declaration

public AnyBitmap DrawRectanglesOnPage(Rectangle[] CropRects, Color rectangleColor)

Parameters

Type	Name	Description
IronSoftware.Drawing.Rectangle[]	CropRects	Crop Rectangle
IronSoftware.Drawing.Color	rectangleColor	Color for pen of rectangle border

Returns

Type	Description
IronSoftware.Drawing.AnyBitmap	Bitmap

FindMultipleTextRegions()

Use computer vision to detect areas which contain text elements and divide the page into separate images based on text regions.

Declaration

public List<OcrInputPage> FindMultipleTextRegions()

Returns

Type	Description
System.Collections.Generic.List<OcrInputPage>	List of rectangles which contain text elements

Remarks

Useful for generating several OCR results from a single image/page

FindTextRegion()

Use computer vision to detect regions which contain text elements and instruct Tesseract to only search for text within the area in which text was detected.

Declaration

public Rectangle FindTextRegion()

Returns

Type	Description
IronSoftware.Drawing.Rectangle	Rectangle which contains text elements

GetCropRectangleImage()

Draw a Rectangle on a OcrInputPage.

Declaration

public AnyBitmap GetCropRectangleImage()

Returns

Type	Description
IronSoftware.Drawing.AnyBitmap	Bitmap

GetTextRegions()

Use computer vision to detect areas which contain text elements and return a list of rectangles.

Declaration

public List<Rectangle> GetTextRegions()

Returns

Type	Description
System.Collections.Generic.List<IronSoftware.Drawing.Rectangle>	List of rectangles which contain text elements

Remarks

Useful for generating several OCR results from a single image/page

SaveAsImage(String)

Saves this page as a Bitmap file to a specified path.

A file path.

Declaration

public void SaveAsImage(string Path)

Parameters

Type	Name	Description
System.String	Path

SaveAsImage(String, AnyBitmap.ImageFormat)

Saves this page as an image file of specified format.

A file path. The desired image file format.

Declaration

public void SaveAsImage(string Path, AnyBitmap.ImageFormat Format)

Parameters

Type	Name	Description
System.String	Path
IronSoftware.Drawing.AnyBitmap.ImageFormat	Format

ToBitmap()

Outputs this page as a IronSoftware.Drawing.AnyBitmap

Declaration

public AnyBitmap ToBitmap()

Returns

Type	Description
IronSoftware.Drawing.AnyBitmap	A native bitmap image.