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TextAlpha Property

Summary
Gets or sets a value that indicate the type of font anti-aliasing to use.
Syntax
C#
Objective-C
C++/CLI
Java
Python
public int TextAlpha { get; set; } 
@property (nonatomic, assign) NSInteger textAlpha; 
public int getTextAlpha() 
public void setTextAlpha(int value) 
public: 
property int TextAlpha { 
   int get(); 
   void set (    int ); 
} 
TextAlpha # get and set (CodecsPdfLoadOptions) 

Property Value

The type of anti-aliasing to use:

Value Description
1 Do not use font anti-aliasing. Default value is 1.
2 Use 2-bit font anti-aliasing.
4 Use 4-bit font anti-aliasing.
Remarks

The value of this property is used only when the Leadtools.Pdf.Utilities.dll is used by the application. For more information, refer to Implementing PDF Features.

Aliasing is the effect on all pixel devices where diagonal and curved lines have a zigzag appearance. As pixels get larger, this effect becomes more noticeable. Anti-aliasing refers to methods designed to decrease or eliminate this effect. Anti-aliasing is done by shading the pixels along the borders of the affected lines.

This affects the PDF format when UsePdfEngine is set to true to use Leadtools.Pdf.Utilities.dll. It also affects the Postscript format.

Example
C#
using Leadtools; 
using Leadtools.Codecs; 
 
using Leadtools.ImageProcessing.Core; 
 
public void CodecsPdfOptionsExample() 
{ 
   RasterCodecs codecs = new RasterCodecs(); 
   string srcFileName = Path.Combine(LEAD_VARS.ImagesDir, "PDFSegmentation.pdf"); 
   string destFileName1 = Path.Combine(LEAD_VARS.ImagesDir, "PdfOptions.pdf"); 
   string destFileName2 = Path.Combine(LEAD_VARS.ImagesDir, "PdfOptions.bmp"); 
   CodecsImageInfo info = codecs.GetInformation(srcFileName, true); 
 
   codecs.Options.Pdf.InitialPath = @"C:\MyApp\Bin"; 
 
   info = codecs.GetInformation(srcFileName, true); 
   Debug.WriteLine("Information for: {0}", srcFileName); 
   Debug.WriteLine(string.Format("Document: {0}", info.Document)); // CodecsDocumentImageInfo reference 
   Debug.WriteLine(string.Format("Document: {0}", info.Document.IsDocumentFile)); 
   Debug.WriteLine(string.Format("Document: {0}", info.Document.PageHeight)); 
   Debug.WriteLine(string.Format("Document: {0}", info.Document.PageWidth)); 
   Debug.WriteLine(string.Format("Document: {0}", info.Document.Unit)); 
   Debug.WriteLine(string.Format("Document: {0}", info.IsGray8Alpha)); 
   Debug.WriteLine(string.Format("Palette: {0}", info.GetPalette())); 
 
   // Check if the PDF engine is installed then get the load and save options of the PDF files. 
   if (codecs.Options.Pdf.IsEngineInstalled) 
   { 
      // Resulting image pixel depth. 
      // CodecsPdfOptions & CodecsPdfLoadOptions reference 
      codecs.Options.Pdf.Load.DisplayDepth = 24; 
      codecs.Options.Pdf.Load.GraphicsAlpha = 4; 
      codecs.Options.Pdf.Load.DisableCieColors = false; 
      codecs.Options.Pdf.Load.DisableCropping = false; 
      codecs.Options.Pdf.Load.EnableInterpolate = false; 
      codecs.Options.Pdf.Load.Password = ""; 
 
      // Type of font anti-aliasing to use. 
      codecs.Options.Pdf.Load.TextAlpha = 1; 
      codecs.Options.Pdf.Load.UseLibFonts = true; 
 
      // Horizontal,vertical  display resolution in dots per inch. 
      codecs.Options.RasterizeDocument.Load.XResolution = 150; 
      codecs.Options.RasterizeDocument.Load.YResolution = 150; 
 
      // CodecsRasterizeDocumentOptions & CodecsRasterizeDocumentLoadOptions reference 
      codecs.Options.RasterizeDocument.Load.BottomMargin = 0.1; 
      codecs.Options.RasterizeDocument.Load.LeftMargin = 0.1; 
      codecs.Options.RasterizeDocument.Load.PageHeight = 11; 
      codecs.Options.RasterizeDocument.Load.PageWidth = 8.5; 
      codecs.Options.RasterizeDocument.Load.Resolution = 150; 
      codecs.Options.RasterizeDocument.Load.RightMargin = 1.25; 
      codecs.Options.RasterizeDocument.Load.SizeMode = CodecsRasterizeDocumentSizeMode.None; // CodecsRasterizeDocumentSizeMode Enumeration reference 
      codecs.Options.RasterizeDocument.Load.TopMargin = 1.0; 
      codecs.Options.RasterizeDocument.Load.Unit = CodecsRasterizeDocumentUnit.Pixel; // CodecsRasterizeDocumentUnit Enumeration reference 
 
      using (RasterImage image = codecs.Load(srcFileName, 0, CodecsLoadByteOrder.BgrOrGray, 1, 1)) 
      { 
         // Set access rights for the user when he\she opens the file we create 
         // CodecsPdfSaveOptions reference 
         codecs.Options.Pdf.Save.AssembleDocument = true; 
         codecs.Options.Pdf.Save.ExtractText = true; 
         codecs.Options.Pdf.Save.ExtractTextGraphics = true; 
         codecs.Options.Pdf.Save.PrintDocument = false; 
         codecs.Options.Pdf.Save.FillForm = true; 
         codecs.Options.Pdf.Save.ModifyAnnotation = true; 
         codecs.Options.Pdf.Save.ModifyDocument = true; 
         codecs.Options.Pdf.Save.OwnerPassword = "LEAD Technologies"; 
         codecs.Options.Pdf.Save.PrintFaithful = false; 
         codecs.Options.Pdf.Save.TextEncoding = CodecsPdfTextEncoding.Hex; 
         codecs.Options.Pdf.Save.Use128BitEncryption = true; 
         codecs.Options.Pdf.Save.UserPassword = "LEAD"; 
 
         // Set the PDF version to be v1.4 
         codecs.Options.Pdf.Save.Version = CodecsRasterPdfVersion.V14; 
 
         // Save it as linearized (optimized for web view) 
         codecs.Options.Pdf.Save.Linearized = true; 
         codecs.Options.Pdf.Save.LowMemoryUsage = false; 
         codecs.Options.Pdf.Save.SavePdfA = false; 
         codecs.Options.Pdf.Save.SavePdfv13 = false; 
         codecs.Options.Pdf.Save.SavePdfv14 = false; 
         codecs.Options.Pdf.Save.SavePdfv15 = false; 
         codecs.Options.Pdf.Save.SavePdfv16 = false; 
         codecs.Options.Pdf.Save.SavePdfv17 = false; 
         codecs.Options.Pdf.Save.UseImageResolution = true; 
 
         // Save the image back as PDF 
         codecs.Save(image, destFileName1, RasterImageFormat.RasPdf, 24); 
      } 
 
      // And load it back before saving it as BMP 
      using (RasterImage image = codecs.Load(destFileName1)) 
      { 
         codecs.Save(image, destFileName2, RasterImageFormat.Bmp, image.BitsPerPixel); 
      } 
   } 
   else 
   { 
      Debug.WriteLine("PDF Engine is not found!"); 
   } 
 
   // Clean up 
   codecs.Dispose(); 
} 
 
static class LEAD_VARS 
{ 
   public const string ImagesDir = @"C:\LEADTOOLS22\Resources\Images"; 
} 
Requirements

Target Platforms

Help Version 22.0.2023.5.5
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Leadtools.Codecs Assembly
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© 1991-2023 LEAD Technologies, Inc. All Rights Reserved.