InvertedPageCommand Class

Summary

Checks and auto-corrects an inverted image.

Syntax

Objective-C

C++/CLI

Java

Python

public class InvertedPageCommand : RasterCommand

@interface LTInvertedPageCommand : LTRasterCommand

public class InvertedPageCommand 
    extends RasterCommand

public ref class InvertedPageCommand : public RasterCommand

class InvertedPageCommand(RasterCommand):

Remarks

This command is available in the Document/Medical Toolkits.

An inverted 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 determine whether an image is inverted and correct it automatically.

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.

Example

This example will show how to use the InvertedPageCommand class to check and auto-correct inverted images.

Java

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:\LEADTOOLS23\Resources\Images"; 
}

 
import java.io.File; 
import java.io.IOException; 
 
import org.junit.*; 
import org.junit.runner.JUnitCore; 
import org.junit.runner.Result; 
import org.junit.runner.notification.Failure; 
import static org.junit.Assert.*; 
 
import leadtools.*; 
import leadtools.codecs.*; 
import leadtools.imageprocessing.color.InvertCommand; 
import leadtools.imageprocessing.core.*; 
 
 
public void invertedPageCommandExample() { 
    final String LEAD_VARS_IMAGES_DIR = "C:\\LEADTOOLS23\\Resources\\Images"; 
 
    // Get an image 
    RasterCodecs codecs = new RasterCodecs(); 
    String tifFileName = combine(LEAD_VARS_IMAGES_DIR, "ocr1.tif"); 
    String invertedImageFileName = combine(LEAD_VARS_IMAGES_DIR, "ocr1_Inverted.tif"); 
    String nonInvertedImageFileName = combine(LEAD_VARS_IMAGES_DIR, "ocr1_NonInverted.tif"); 
    RasterImage image = codecs.load(tifFileName); 
 
    // The images should be non=inverted at the beginning, check 
    InvertedPageCommand invertedPage = new InvertedPageCommand(InvertedPageCommandFlags.NO_PROCESS.getValue()); 
    invertedPage.run(image); 
    System.out.println("Original image, inverted = " + invertedPage.isInverted()); 
 
    // Invert the image 
    InvertCommand invert = new InvertCommand(); 
    invert.run(image); 
    codecs.save(image, invertedImageFileName, image.getOriginalFormat(), image.getBitsPerPixel()); 
 
    System.out.println("Command run and image saved to: " + invertedImageFileName); 
    // Check again 
    invertedPage.run(image); 
    System.out.println("After running InvertCommand, inverted = " + invertedPage.isInverted()); 
 
    // Now run the command to un-invert the iamge 
    invertedPage.setFlags(InvertedPageCommandFlags.PROCESS.getValue()); 
    invertedPage.run(image); 
 
    // Now check the image again 
    invertedPage.setFlags(InvertedPageCommandFlags.NO_PROCESS.getValue()); 
    invertedPage.run(image); 
    System.out.println("After running InvertedPageCommand, inverted = " + invertedPage.isInverted()); 
    codecs.save(image, nonInvertedImageFileName, image.getOriginalFormat(), image.getBitsPerPixel()); 
 
    System.out.println("Command run and image saved to: " + nonInvertedImageFileName); 
    assertTrue(new File(nonInvertedImageFileName).exists()); 
 
    image.dispose(); 
    codecs.dispose(); 
 
}