GetRotateAngle Method

Summary

Gets the angle of the rotation of this IOcrPage.

Syntax

Objective-C

C++/CLI

Java

Python

public int GetRotateAngle()

- (NSInteger)rotateAngle:(NSError **)error NS_SWIFT_NOTHROW;

public int getRotateAngle()

int GetRotateAngle();

def GetRotateAngle(self):

Return Value

The angle of rotation of this image in degrees. A positive value indicates a counter-clockwise rotation.

Remarks

This method will return one of the following values:

Value	Description
0	The image is not rotated.
90	The image is rotated 90 degrees (counter-clockwise rotation).
180	The image is rotated 180 degrees (upside down).
270	The image is rotated 270 degrees (counter-clockwise rotation).

Use AutoPreprocess with OcrAutoPreprocessPageCommand.Rotate to automatically rotate the page image prior to calling Recognize. This could enhance the quality of the image before starting its recognition.

If the image is rotated, GetRotateAngle returns the angle required to fix the orientation of the page. If you call AutoPreprocess on the page, all subsequent calls to GetRotateAngle will return 0 since the image is not rotated. Hence, you must call GetRotateAngle before calling AutoPreprocess.

Use GetPreprocessValues to obtain the accumulative pre-processing values applied to this IOcrPage.

Example

using Leadtools; 
using Leadtools.Codecs; 
using Leadtools.Ocr; 
using Leadtools.Forms.Common; 
using Leadtools.Document.Writer; 
using Leadtools.WinForms; 
using Leadtools.Drawing; 
using Leadtools.ImageProcessing; 
using Leadtools.ImageProcessing.Color; 
 
public void AutoPreprocessExample() 
{ 
   string tifFileName = Path.Combine(LEAD_VARS.ImagesDir, "Clean.tif"); 
   string pdfFileName = Path.Combine(LEAD_VARS.ImagesDir, "Clean.pdf"); 
 
   // Create an instance of the engine 
   using (IOcrEngine ocrEngine = OcrEngineManager.CreateEngine(OcrEngineType.LEAD)) 
   { 
      // Start the engine using default parameters 
      ocrEngine.Startup(null, null, null, LEAD_VARS.OcrLEADRuntimeDir); 
 
      // Create an OCR document 
      using (IOcrDocument ocrDocument = ocrEngine.DocumentManager.CreateDocument()) 
      { 
         // Add this image to the document 
         IOcrPage ocrPage = ocrDocument.Pages.AddPage(tifFileName, null); 
 
         // Auto-preprocess it 
         ocrPage.AutoPreprocess(OcrAutoPreprocessPageCommand.Deskew, null); 
         ocrPage.AutoPreprocess(OcrAutoPreprocessPageCommand.Invert, null); 
         ocrPage.AutoPreprocess(OcrAutoPreprocessPageCommand.Rotate, null); 
 
         // Recognize it and save it as PDF 
         ocrPage.Recognize(null); 
         ocrDocument.Save(pdfFileName, DocumentFormat.Pdf, null); 
      } 
 
      // Shutdown the engine 
      // Note: calling Dispose will also automatically shutdown the engine if it has been started 
      ocrEngine.Shutdown(); 
   } 
} 
 
static class LEAD_VARS 
{ 
   public const string ImagesDir = @"C:\LEADTOOLS23\Resources\Images"; 
   public const string OcrLEADRuntimeDir = @"C:\LEADTOOLS23\Bin\Common\OcrLEADRuntime"; 
}