InvertedPageCommand Class

Checks and auto-corrects an inverted image.

Object Model

Syntax

C#
Visual Basic
WinRT C#
Objective-C
Java
WinRT JavaScript
C++

public class InvertedPageCommand : Leadtools.ImageProcessing.RasterCommand, Leadtools.ImageProcessing.IRasterCommand

'Declaration
 
Public Class InvertedPageCommand 
   Inherits Leadtools.ImageProcessing.RasterCommand
   Implements Leadtools.ImageProcessing.IRasterCommand

'Usage
 
Dim instance As InvertedPageCommand

public sealed class InvertedPageCommand : Leadtools.ImageProcessing.IRasterCommand

@interface LTInvertedPageCommand : LTRasterCommand

public class InvertedPageCommand extends RasterCommand

function Leadtools.ImageProcessing.Core.InvertedPageCommand()

public ref class InvertedPageCommand : public Leadtools.ImageProcessing.RasterCommand, Leadtools.ImageProcessing.IRasterCommand

Remarks

An inverted Leadtools.RasterImage is an image that has text or other objects in high contrast color on a low contrast background, for example white text on black background. This command can check whether an image is inverted as well as auto-correct it.

This command can only detect an entire image. To search for and correct specific inverted areas or regions in an image, use the InvertedTextCommand.

A common source of inverted images are black and white images saved with a non-standard palette by some applications.

This command does not support signed data images.

For more information, refer to Cleaning Up 1-Bit Images.

In Silverlight and Windows Phone versions of LEADTOOLS, this image processing command will fail if the image data for the RasterImage object is stored internally using a Silverlight WriteableBitmap object. For more information, refer to Image Processing Command Limitations in Silverlight.

Example

C#
Visual Basic
WinRT C#
WinRT JavaScript
Silverlight C#
Silverlight VB

Copy Code

Imports Leadtools
Imports Leadtools.Codecs
Imports Leadtools.ImageProcessing.Core
Imports Leadtools.ImageProcessing.Color

Public Sub InvertedPageCommandExample()
   Dim codecs As New RasterCodecs()

   ' Get an image
   Dim tifFileName As String = Path.Combine(LEAD_VARS.ImagesDir, "ocr1.tif")
   Dim invertedImageFileName As String = Path.Combine(LEAD_VARS.ImagesDir, "ocr1_Inverted.tif")
   Dim nonInvertedImageFileName As String = Path.Combine(LEAD_VARS.ImagesDir, "ocr1_NonInverted.tif")

   Dim image As RasterImage = codecs.Load(tifFileName)

   ' The images should be non-inverted at the beginning, check
   Dim invertedPage As New InvertedPageCommand(InvertedPageCommandFlags.NoProcess)
   invertedPage.Run(image)
   Console.WriteLine("Original image, inverted = {0}", invertedPage.IsInverted)

   ' Invert the image
   Dim invert As New InvertCommand()
   invert.Run(image)

   codecs.Save(image, invertedImageFileName, image.OriginalFormat, image.BitsPerPixel)

   ' Check again
   invertedPage.Run(image)
   Console.WriteLine("After running InvertCommand, inverted = {0}", invertedPage.IsInverted)

   ' Now run the command to un-invert the image
   invertedPage.Flags = InvertedPageCommandFlags.Process
   invertedPage.Run(image)

   ' Now check the image again
   invertedPage.Flags = InvertedPageCommandFlags.NoProcess
   invertedPage.Run(image)
   Console.WriteLine("After running InvertedPageCommand, inverted = {0}", invertedPage.IsInverted)
   codecs.Save(image, nonInvertedImageFileName, image.OriginalFormat, image.BitsPerPixel)

   image.Dispose()

   codecs.Dispose()
End Sub

Public NotInheritable Class LEAD_VARS
Public Const ImagesDir As String = "C:\Users\Public\Documents\LEADTOOLS Images"
End Class

using Leadtools;
using Leadtools.Codecs;
using Leadtools.ImageProcessing.Core;
using Leadtools.ImageProcessing.Color;

public void InvertedPageCommandExample()
{
   RasterCodecs codecs = new RasterCodecs();

   // Get an image
   string tifFileName = Path.Combine(LEAD_VARS.ImagesDir, "ocr1.tif");
   string invertedImageFileName = Path.Combine(LEAD_VARS.ImagesDir, "ocr1_Inverted.tif");
   string nonInvertedImageFileName = Path.Combine(LEAD_VARS.ImagesDir, "ocr1_NonInverted.tif");

   RasterImage image = codecs.Load(tifFileName);

   // The images should be non-inverted at the beginning, check
   InvertedPageCommand invertedPage = new InvertedPageCommand(InvertedPageCommandFlags.NoProcess);
   invertedPage.Run(image);
   Console.WriteLine("Original image, inverted = {0}", invertedPage.IsInverted);

   // Invert the image
   InvertCommand invert = new InvertCommand();
   invert.Run(image);

   codecs.Save(image, invertedImageFileName, image.OriginalFormat, image.BitsPerPixel);

   // Check again
   invertedPage.Run(image);
   Console.WriteLine("After running InvertCommand, inverted = {0}", invertedPage.IsInverted);

   // Now run the command to un-invert the image
   invertedPage.Flags = InvertedPageCommandFlags.Process;
   invertedPage.Run(image);

   // Now check the image again
   invertedPage.Flags = InvertedPageCommandFlags.NoProcess;
   invertedPage.Run(image);
   Console.WriteLine("After running InvertedPageCommand, inverted = {0}", invertedPage.IsInverted);
   codecs.Save(image, nonInvertedImageFileName, image.OriginalFormat, image.BitsPerPixel);

   image.Dispose();

   codecs.Dispose();
}

static class LEAD_VARS
{
public const string ImagesDir = @"C:\Users\Public\Documents\LEADTOOLS Images";
}

function InvertedPageCommandExample()
{
   var codecs = new Leadtools.Codecs.RasterCodecs();
   var invertedPage;
   var workingImage;

   // Load the image
   var srcFileName = "Assets\\ocr1.tif";
   return Tools.AppInstallFolder().getFileAsync(srcFileName).then(function (loadFile) {
      return codecs.loadAsync(Leadtools.LeadStreamFactory.create(loadFile));
   }).then(function (image) {
      with (Leadtools.ImageProcessing.Core)
      {
         // The images should be non-inverted at the beginning, check
         invertedPage = new InvertedPageCommand(InvertedPageCommandFlags.noProcess);
         invertedPage.run(image);
         console.error("Original image, inverted = {0}", invertedPage.isInverted);
      }

      // Invert the image
      var invert = new Leadtools.ImageProcessing.Color.InvertCommand();
      invert.run(image);

      workingImage = image;

      var destFileName = "ocr1_Inverted.tif";
      return Tools.AppLocalFolder().createFileAsync(destFileName)
   }).then(function (saveFile) {
      return codecs.saveAsync(workingImage, Leadtools.LeadStreamFactory.create(saveFile), workingImage.originalFormat, workingImage.bitsPerPixel)
   }).then(function () {

      // Check again
      invertedPage.run(workingImage);
      console.error("After running InvertCommand, inverted = {0}", invertedPage.isInverted);

      // Now run the command to un-invert the image
      with (Leadtools.ImageProcessing.Core)
      {
         invertedPage.flags = InvertedPageCommandFlags.process;
         invertedPage.run(workingImage);

         // Now check the image again
         invertedPage.flags = InvertedPageCommandFlags.noProcess;
         invertedPage.run(workingImage);
      }

      console.error("After running InvertedPageCommand, inverted = {0}", invertedPage.isInverted);
      destFileName = "ocr1_NonInverted.tif";
      return Tools.AppLocalFolder().createFileAsync(destFileName);
   }).then(function (saveFile) {
      return codecs.saveAsync(workingImage, Leadtools.LeadStreamFactory.create(saveFile), workingImage.originalFormat, workingImage.bitsPerPixel);
   });
}

using Leadtools;
using Leadtools.Codecs;
using Leadtools.ImageProcessing.Core;
using Leadtools.ImageProcessing.Color;

      
public async Task InvertedPageCommandExample()
{
   RasterCodecs codecs = new RasterCodecs();
   // Load the image
   string srcFileName = @"Assets\ocr1.tif";
   StorageFile loadFile = await Tools.AppInstallFolder.GetFileAsync(srcFileName);
   RasterImage image = await codecs.LoadAsync(LeadStreamFactory.Create(loadFile));

   // The images should be non-inverted at the beginning, check
   InvertedPageCommand invertedPage = new InvertedPageCommand(InvertedPageCommandFlags.NoProcess);
   invertedPage.Run(image);
   Debug.WriteLine("Original image, inverted = {0}", invertedPage.IsInverted);

   // Invert the image
   InvertCommand invert = new InvertCommand();
   invert.Run(image);
   string destFileName = @"ocr1_Inverted.tif";
   StorageFile saveFile = await Tools.AppLocalFolder.CreateFileAsync(destFileName);
   await codecs.SaveAsync(image, LeadStreamFactory.Create(saveFile), image.OriginalFormat, image.BitsPerPixel);

   // Check again
   invertedPage.Run(image);
   Debug.WriteLine("After running InvertCommand, inverted = {0}", invertedPage.IsInverted);

   // Now run the command to un-invert the image
   invertedPage.Flags = InvertedPageCommandFlags.Process;
   invertedPage.Run(image);

   // Now check the image again
   invertedPage.Flags = InvertedPageCommandFlags.NoProcess;
   invertedPage.Run(image);
   Debug.WriteLine("After running InvertedPageCommand, inverted = {0}", invertedPage.IsInverted);
   destFileName = @"ocr1_NonInverted.tif";
   saveFile = await Tools.AppLocalFolder.CreateFileAsync(destFileName);
   await codecs.SaveAsync(image, LeadStreamFactory.Create(saveFile), image.OriginalFormat, image.BitsPerPixel);

   image.Dispose();

   codecs.Dispose();
}

using Leadtools;
using Leadtools.ImageProcessing;
using Leadtools.Examples;
using Leadtools.Codecs;
using Leadtools.ImageProcessing.Core;
using Leadtools.ImageProcessing.Color;

public void InvertedPageCommandExample(RasterImage image, Stream outStream1, Stream outStream2)
{
   // The images should be non-inverted at the beginning, check
   InvertedPageCommand invertedPage = new InvertedPageCommand(InvertedPageCommandFlags.NoProcess);
   invertedPage.Run(image);
   Debug.WriteLine("Original image, inverted = {0}", invertedPage.IsInverted);
   // Invert the image
   InvertCommand invert = new InvertCommand();
   invert.Run(image);

   RasterCodecs codecs = new RasterCodecs();
   // save image to "ocr1_Inverted.tif";
   codecs.Save(image, outStream1, image.OriginalFormat, image.BitsPerPixel);

   // Check again
   invertedPage.Run(image);
   Debug.WriteLine("After running InvertCommand, inverted = {0}", invertedPage.IsInverted);

   // Now run the command to un-invert the image
   invertedPage.Flags = InvertedPageCommandFlags.Process;
   invertedPage.Run(image);

   // Now check the image again
   invertedPage.Flags = InvertedPageCommandFlags.NoProcess;
   invertedPage.Run(image);
   Debug.WriteLine("After running InvertedPageCommand, inverted = {0}", invertedPage.IsInverted);

   // save result image to "ocr1_NonInverted.tif"
   codecs.Save(image, outStream2, RasterImageFormat.CcittGroup4, 1);

   image.Dispose();
}

Imports Leadtools
Imports Leadtools.ImageProcessing
Imports Leadtools.Codecs
Imports Leadtools.ImageProcessing.Core
Imports Leadtools.ImageProcessing.Color

Public Sub InvertedPageCommandExample(ByVal image As RasterImage, ByVal outStream1 As Stream, ByVal outStream2 As Stream)
   ' The images should be non-inverted at the beginning, check
   Dim invertedPage As InvertedPageCommand = New InvertedPageCommand(InvertedPageCommandFlags.NoProcess)
   invertedPage.Run(image)
   Debug.WriteLine("Original image, inverted = {0}", invertedPage.IsInverted)
   ' Invert the image
   Dim invert As InvertCommand = New InvertCommand()
   invert.Run(image)

   Dim codecs As RasterCodecs = New RasterCodecs()
   ' save image to "ocr1_Inverted.tif";
   codecs.Save(image, outStream1, image.OriginalFormat, image.BitsPerPixel)

   ' Check again
   invertedPage.Run(image)
   Debug.WriteLine("After running InvertCommand, inverted = {0}", invertedPage.IsInverted)

   ' Now run the command to un-invert the image
   invertedPage.Flags = InvertedPageCommandFlags.Process
   invertedPage.Run(image)

   ' Now check the image again
   invertedPage.Flags = InvertedPageCommandFlags.NoProcess
   invertedPage.Run(image)
   Debug.WriteLine("After running InvertedPageCommand, inverted = {0}", invertedPage.IsInverted)

   ' save result image to "ocr1_NonInverted.tif"
   codecs.Save(image, outStream2, RasterImageFormat.CcittGroup4, 1)

   image.Dispose()
End Sub

Requirements

Target Platforms

Reference

InvertedPageCommand Members
Leadtools.ImageProcessing.Core Namespace
Cleaning Up 1-Bit Images
SmoothCommand Class
BorderRemoveCommand Class
LineRemoveCommand Class
InvertedTextCommand Class
HighQualityRotateCommand Class
DotRemoveCommand Class
HolePunchRemoveCommand Class
HighQualityRotateCommand Class
MinimumCommand Class
MaximumCommand Class
Leadtools.ImageProcessing.Effects.RegionHolesRemovalCommand