GrayImageDownsampleFactor Property

Summary

Scale factor to use for resizing when saving a grayscale image.

Syntax

C++/CLI

Java

Python

public double GrayImageDownsampleFactor { get; set; }

public double getGrayImageDownsampleFactor(); 
public void setGrayImageDownsampleFactor( 
   double doubleValue 
);

public: 
property double GrayImageDownsampleFactor { 
   double get(); 
   void set (    double ); 
}

GrayImageDownsampleFactor # get and set (PDFOptimizerOptions)

Property Value

This is the ratio of image resolution to output resolution above which downsampling may be performed. Must be between 1.0 through 10.0, inclusive.

Remarks

If you set the threshold out of range, it reverts to a default of 1.5.

Example

Java

using Leadtools.WinForms; 
using Leadtools; 
using Leadtools.Codecs; 
using Leadtools.Controls; 
using Leadtools.Drawing; 
using Leadtools.ImageProcessing; 
using Leadtools.Pdf; 
using Leadtools.Svg; 
 
 
public void PDFFileOptimizerOptionsExample() 
{ 
   string sourceFileName = Path.Combine(LEAD_VARS.ImagesDir, @"Leadtools.pdf"); 
   string destinationFileName = Path.Combine(LEAD_VARS.ImagesDir, @"LEAD_OptimizerOptions.pdf"); 
 
   PDFFile pdfFile = new PDFFile(sourceFileName); 
 
   PDFOptimizerOptions myOptimizerOptions = new PDFOptimizerOptions(); 
   myOptimizerOptions.AutoOptimizerMode = PDFAutoOptimizerMode.Customized; 
 
   myOptimizerOptions.ColorImageDownsamplingMode = PDFDownsamplingMode.Average; 
   myOptimizerOptions.GrayImageDownsamplingMode = PDFDownsamplingMode.Bicubic; 
   myOptimizerOptions.MonoImageDownsamplingMode = PDFDownsamplingMode.Bicubic; 
 
   myOptimizerOptions.ColorImageDownsampleFactor = 2.0; 
   myOptimizerOptions.GrayImageDownsampleFactor = 2.0; 
   myOptimizerOptions.MonoImageDownsampleFactor = 2.0; 
 
   myOptimizerOptions.ColorImageDPI = 150; 
   myOptimizerOptions.GrayImageDPI = 150; 
   myOptimizerOptions.MonoImageDPI = 150; 
 
   // To determine the accepted compression value for ColorImageCompression, GrayImageCompression and MonoImageCompression 
   // uncomment the necessary code below: 
   // 
   // ColorImageCompression 
   // RasterImageFormat[] grayImageFormatAcceptedCompression = PDFOptimizerOptions.SupportedGrayImageFormats; 
   // 
   // GrayImageCompression 
   // RasterImageFormat[] colorImageFormatAcceptedCompression = PDFOptimizerOptions.SupportedColorImageFormats; 
   // 
   // MonoImageCompression 
   // RasterImageFormat[] monoImageFormatAcceptedCompression = PDFOptimizerOptions.SupportedMonoImageFormats; 
 
   myOptimizerOptions.ColorImageCompression = RasterImageFormat.Jpeg; 
   myOptimizerOptions.GrayImageCompression = RasterImageFormat.Jpeg; 
   myOptimizerOptions.MonoImageCompression = RasterImageFormat.Jbig2; 
 
   myOptimizerOptions.EmbedAllFonts = false; 
   myOptimizerOptions.SubsetFonts = true; 
 
   pdfFile.OptimizerOptions = myOptimizerOptions; 
 
   pdfFile.Optimize(destinationFileName); 
} 
 
static class LEAD_VARS 
{ 
   public const string ImagesDir = @"C:\LEADTOOLS23\Resources\Images"; 
}

 
import java.io.ByteArrayInputStream; 
import java.io.File; 
import java.io.FileInputStream; 
import java.io.FileNotFoundException; 
import java.io.FileOutputStream; 
import java.io.FileReader; 
import java.io.IOException; 
import java.io.InputStream; 
import java.nio.file.Files; 
import java.nio.file.Paths; 
import java.nio.file.StandardCopyOption; 
import java.util.ArrayList; 
import java.util.Date; 
import java.util.List; 
import java.util.Scanner; 
 
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.pdf.*; 
 
 
public void pdfFileOptimizerOptionsExample() { 
 
   final String LEAD_VARS_IMAGES_DIR = "C:\\LEADTOOLS23\\Resources\\Images"; 
   String sourceFileName = combine(LEAD_VARS_IMAGES_DIR, "Leadtools.pdf"); 
   String destinationFileName = combine(LEAD_VARS_IMAGES_DIR, 
         "LEAD_OptimizerOptions.pdf"); 
 
   PDFFile pdfFile = new PDFFile(sourceFileName); 
 
   PDFOptimizerOptions myOptimizerOptions = new PDFOptimizerOptions(); 
   myOptimizerOptions.setAutoOptimizerMode(PDFAutoOptimizerMode.CUSTOMIZED); 
 
   myOptimizerOptions.setColorImageDownsamplingMode(PDFDownsamplingMode.AVERAGE); 
   myOptimizerOptions.setGrayImageDownsamplingMode(PDFDownsamplingMode.BICUBIC); 
   myOptimizerOptions.setMonoImageDownsamplingMode(PDFDownsamplingMode.BICUBIC); 
 
   myOptimizerOptions.setColorImageDownsampleFactor(2.0); 
   myOptimizerOptions.setGrayImageDownsampleFactor(2.0); 
   myOptimizerOptions.setMonoImageDownsampleFactor(2.0); 
 
   myOptimizerOptions.setColorImageDPI(150); 
   myOptimizerOptions.setGrayImageDPI(150); 
   myOptimizerOptions.setMonoImageDPI(150); 
 
   // To determine the accepted compression value for ColorImageCompression, 
   // GrayImageCompression and MonoImageCompression: 
   // uncomment the necessary code below: 
   // 
   // ColorImageCompression 
   // RasterImageFormat[] grayImageFormatAcceptedCompression = 
   // PDFOptimizerOptions.SupportedGrayImageFormats; 
   // 
   // GrayImageCompression 
   // RasterImageFormat[] colorImageFormatAcceptedCompression = 
   // PDFOptimizerOptions.SupportedColorImageFormats; 
   // 
   // MonoImageCompression 
   // RasterImageFormat[] monoImageFormatAcceptedCompression = 
   // PDFOptimizerOptions.SupportedMonoImageFormats; 
 
   myOptimizerOptions.setColorImageCompression(RasterImageFormat.JPEG); 
   myOptimizerOptions.setGrayImageCompression(RasterImageFormat.JPEG); 
   myOptimizerOptions.setMonoImageCompression(RasterImageFormat.JBIG2); 
 
   myOptimizerOptions.setEmbedAllFonts(false); 
   myOptimizerOptions.setSubsetFonts(true); 
 
   pdfFile.setOptimizerOptions(myOptimizerOptions); 
 
   pdfFile.optimize(destinationFileName); 
   assertTrue(pdfFile.getOptimizerOptions().equals(myOptimizerOptions)); 
 
}

Requirements

Target Platforms

Reference

PDFOptimizerOptions Class

PDFOptimizerOptions Members

Download our FREE evaluation

Help Version 23.0.2024.2.29

Leadtools.Pdf Assembly

Introduction

Getting Started

Namespaces

Leadtools.Pdf Namespace

Assemblies