GetTextOrientationCommand Class

In This Topic

Detects text orientation in a document image.

Object Model

Syntax

Visual Basic
C#
Managed Extensions for C++
C++/CLI

'Declaration
 
Public Class GetTextOrientationCommand 
   Inherits Vintasoft.Imaging.ImageProcessing.ProcessingCommandBase

public class GetTextOrientationCommand : Vintasoft.Imaging.ImageProcessing.ProcessingCommandBase

public __gc class GetTextOrientationCommand : public Vintasoft.Imaging.ImageProcessing.ProcessingCommandBase

public ref class GetTextOrientationCommand : public Vintasoft.Imaging.ImageProcessing.ProcessingCommandBase

Remarks

This processing command is designed to determine orientation of images containing mostly text in Roman alphabet which is rotated by multiple of 90 degrees (e.g., scanned documents with unknown orientation).
The command is not designed for:

non-textual images
non-Roman text
Roman text with only capital letters
rotated text with rotation angle other than multiple of 90 degrees (use Vintasoft.Imaging.ImageProcessing.Document.DeskewCommand)
images with only few words, insufficient for making a conclusion

Use Vintasoft.Imaging.ImageProcessing.Document.DeskewCommand prior to this command to align the rotated image. Use other processing commands prior to this command to improve the detection quality of image with noise.

Example

This example shows how to load an image from disk and determine the text orientation.

VB.NET

' [ do not forget to set your image file path here! ]
Dim filepath As String = "Document.tif"
            
' create the command
Dim command As New Vintasoft.Imaging.ImageProcessing.Info.GetTextOrientationCommand()
            
' initialize command results
command.Results = New Vintasoft.Imaging.ImageProcessing.ProcessingCommandResults()
            
Try
    Using image As New Vintasoft.Imaging.VintasoftImage(filepath)
        ' execute the command
        command.ExecuteInPlace(image)
    End Using
Catch ex As Vintasoft.Imaging.ImageProcessing.ImageProcessingException
    ' show error message if problem occured
    System.Windows.Forms.MessageBox.Show(ex.Message)
    Return
End Try
            
' get command result
Dim result As Vintasoft.Imaging.ImageProcessing.Info.GetTextOrientationCommandResult = DirectCast(command.Results(0), Vintasoft.Imaging.ImageProcessing.Info.GetTextOrientationCommandResult)
Dim documentOrientation As Vintasoft.Imaging.ImageProcessing.Info.ImageOrthogonalOrientation = result.Orientation
            
' show orientation determining result
Select Case documentOrientation
    Case Vintasoft.Imaging.ImageProcessing.Info.ImageOrthogonalOrientation.Undefined
        System.Windows.Forms.MessageBox.Show(System.[String].Format("Document orientation is not defined."))
        Exit Select
    Case Vintasoft.Imaging.ImageProcessing.Info.ImageOrthogonalOrientation.Rotated0
        System.Windows.Forms.MessageBox.Show(System.[String].Format("Document has the right orientation."))
        Exit Select
    Case Vintasoft.Imaging.ImageProcessing.Info.ImageOrthogonalOrientation.Rotated90
        System.Windows.Forms.MessageBox.Show(System.[String].Format("Document is rotated by 90 degrees clockwise."))
        Exit Select
    Case Vintasoft.Imaging.ImageProcessing.Info.ImageOrthogonalOrientation.Rotated180
        System.Windows.Forms.MessageBox.Show(System.[String].Format("Document is rotated by 180 degrees clockwise."))
        Exit Select
    Case Vintasoft.Imaging.ImageProcessing.Info.ImageOrthogonalOrientation.Rotated270
        System.Windows.Forms.MessageBox.Show(System.[String].Format("Document is rotated by 270 degrees clockwise."))
        Exit Select
    Case Else
        Throw New System.NotImplementedException()
End Select

// [ do not forget to set your image file path here! ]
string filepath = "Document.tif";
            
// create the command
Vintasoft.Imaging.ImageProcessing.Info.GetTextOrientationCommand command =
    new Vintasoft.Imaging.ImageProcessing.Info.GetTextOrientationCommand();
            
// initialize command results
command.Results = new Vintasoft.Imaging.ImageProcessing.ProcessingCommandResults();
            
try
{
    using (Vintasoft.Imaging.VintasoftImage image = 
        new Vintasoft.Imaging.VintasoftImage(filepath))
    {
        // execute the command
        command.ExecuteInPlace(image);
    }
}
catch (Vintasoft.Imaging.ImageProcessing.ImageProcessingException ex)
{
    // show error message if problem occured
    System.Windows.Forms.MessageBox.Show(ex.Message);
    return;
}
            
// get command result
Vintasoft.Imaging.ImageProcessing.Info.GetTextOrientationCommandResult result = 
    (Vintasoft.Imaging.ImageProcessing.Info.GetTextOrientationCommandResult)command.Results[0];
Vintasoft.Imaging.ImageProcessing.Info.ImageOrthogonalOrientation documentOrientation = 
    result.Orientation;
            
// show orientation determining result
switch (documentOrientation)
{
    case Vintasoft.Imaging.ImageProcessing.Info.ImageOrthogonalOrientation.Undefined: 
        System.Windows.Forms.MessageBox.Show(System.String.Format("Document orientation is not defined."));
        break;
    case Vintasoft.Imaging.ImageProcessing.Info.ImageOrthogonalOrientation.Rotated0:
        System.Windows.Forms.MessageBox.Show(System.String.Format("Document has the right orientation."));
        break;
    case Vintasoft.Imaging.ImageProcessing.Info.ImageOrthogonalOrientation.Rotated90:
        System.Windows.Forms.MessageBox.Show(System.String.Format("Document is rotated by 90 degrees clockwise."));
        break;
    case Vintasoft.Imaging.ImageProcessing.Info.ImageOrthogonalOrientation.Rotated180:
        System.Windows.Forms.MessageBox.Show(System.String.Format("Document is rotated by 180 degrees clockwise."));
        break;
    case Vintasoft.Imaging.ImageProcessing.Info.ImageOrthogonalOrientation.Rotated270:
        System.Windows.Forms.MessageBox.Show(System.String.Format("Document is rotated by 270 degrees clockwise."));
        break;
    default:
        throw new System.NotImplementedException();
}

Inheritance Hierarchy

System.Object
Vintasoft.Imaging.ImageProcessing.ProcessingCommandBase
Vintasoft.Imaging.ImageProcessing.Info.GetTextOrientationCommand

Requirements

Target Platforms: .NET 6; .NET 5; .NET Core 3.1; .NET Framework 4.8, 4.7, 4.6, 4.5, 4.0, 3.5

Reference

GetTextOrientationCommand Members
Vintasoft.Imaging.ImageProcessing.Info Namespace
AutoTextOrientationCommand Class

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