Blurry Pdf after zooming - javafx

Question

I have a pdf reader developped using Apache PdfBox, my problem is that i have a blurry image after zooming , this problem is only with PDF even if the resolution is very good of the pdf file.
this code working good with png or jpg files, but the problem still with pdf files, i'am really confused, i search on google but i found some solutions that are not complete.
Controller
package application;
import java.nio.file.Paths;
import javafx.beans.InvalidationListener;
import javafx.beans.Observable;
import javafx.beans.property.DoubleProperty;
import javafx.beans.property.SimpleDoubleProperty;
import javafx.fxml.FXML;
import javafx.scene.control.ScrollPane;
import javafx.scene.control.ScrollPane.ScrollBarPolicy;
import javafx.scene.image.ImageView;
import javafx.scene.layout.VBox;
public class Controller {
String imagePath = "C:\\Users\\piratack007\\Desktop\\1.jpg";
private ImageView imageView = new ImageView();
String path="C:\\Users\\piratack007\\Desktop\\file.pdf";
private PdfModel model= new PdfModel(Paths.get(path));
private ScrollPane scrollPane = new ScrollPane();
private DoubleProperty zoom = new SimpleDoubleProperty(1.1);
private PageDimensions currentPageDimensions ;
#FXML private VBox vbox;
String cssLayout = "-fx-border-color: red;\n" +
"-fx-border-insets: 5;\n" +
"-fx-border-width: 3;\n" +
"-fx-border-style: dashed;\n";
String scrollCssLayout= "-fx-border-color: green;\n" +
"-fx-border-insets: 5;\n" +
"-fx-border-width: 3;\n" +
"-fx-border-style: dashed;\n"+
//Ne pas afficher le petit trait gris
"-fx-background-color:transparent";
public void initialize() {
afficheImage();
}
void afficheImage() {
/*try {
imageView = new ImageView(new Image(new FileInputStream(imagePath)));
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}*/
//loading the first page
imageView = new ImageView(model.getImage(0));
System.out.print("1-imageView.getFitHeight(): "+imageView.getImage().getHeight()+"\n");
System.out.print("imageView.getFitWidth(): "+imageView.getImage().getWidth()+"\n");
currentPageDimensions = new PageDimensions(imageView.getImage().getWidth(), imageView.getImage().getHeight());
zoom.addListener(new InvalidationListener() {
#Override
public void invalidated(Observable arg0) {
//My problem is in this part of code
int width = (int) (imageView.getImage().getWidth() * zoom.get());
int height = (int) (imageView.getImage().getHeight() * zoom.get());
imageView.setFitWidth(width);
System.out.print("Largeur: "+ (width) +"px\n");
imageView.setFitHeight(height);
System.out.print("Hauteur: "+ height +"px\n");
//==================================================
}
});
imageView.preserveRatioProperty().set(true);
scrollPane.setPannable(true);
scrollPane.setStyle(scrollCssLayout);
scrollPane.setVbarPolicy(ScrollBarPolicy.AS_NEEDED);
scrollPane.setHbarPolicy(ScrollBarPolicy.AS_NEEDED);
scrollPane.setContent(imageView);
vbox.setStyle(cssLayout);
vbox.getChildren().add(scrollPane);
}
#FXML private void zoomIn() {
zoom.set(zoom.get()*1.1);
// System.out.print("zoom.get(): "+zoom.get()*100 +"%\n");
}
#FXML private void zoomOut() {
zoom.set(zoom.get()/1.1);
// System.out.print("zoom.get(): "+zoom.get()*100 +"%\n");
}
#FXML private void zoomFit() {
}
#FXML private void zoomWidth() {
}
private class PageDimensions {
private double width ;
private double height ;
PageDimensions(double width, double height) {
this.width = width ;
this.height = height ;
}
#Override
public String toString() {
return String.format("[%.1f, %.1f]", width, height);
}
}
}
PdfModel
package application;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.io.UncheckedIOException;
import java.nio.file.Path;
import javafx.embed.swing.SwingFXUtils;
import javafx.scene.image.Image;
import org.apache.pdfbox.pdmodel.PDDocument;
import org.apache.pdfbox.pdmodel.PDPage;
import org.apache.pdfbox.pdmodel.common.PDRectangle;
import org.apache.pdfbox.rendering.PDFRenderer;
/**
* #author toru
*/
class PdfModel {
//private static final Logger logger = Logger.getLogger(PdfModel.class.getName());
private PDDocument document;
private PDFRenderer renderer;
Path chemin;
PdfModel() {
}
PdfModel(Path path) {
try {
chemin=path;
document = PDDocument.load(path.toFile());
renderer = new PDFRenderer(document);
} catch (IOException ex) {
throw new UncheckedIOException("PDDocument thorws IOException file=" + path, ex);
}
}
int nombreDePages() {
return document.getPages().getCount();
}
PDPage getPage (int num) {
PDPage page = document.getPage(num);
return page;
}
void fermer() {
try {
document.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
void setPath(Path pPays)
{
chemin = pPays;
System.out.println("On est dans la page pdfmodel");
System.out.println("Path: "+pPays);
}
Image getImage(int pageNumber) {
BufferedImage pageImage;
try {
pageImage = renderer.renderImage(pageNumber);
} catch (IOException ex) {
throw new UncheckedIOException("PDFRenderer throws IOException", ex);
}
return SwingFXUtils.toFXImage(pageImage, null);
}
}
ui.fxml
<?xml version="1.0" encoding="UTF-8"?>
<?import javafx.geometry.Insets?>
<?import javafx.scene.control.Button?>
<?import javafx.scene.layout.BorderPane?>
<?import javafx.scene.layout.HBox?>
<?import javafx.scene.layout.VBox?>
<BorderPane maxHeight="-Infinity" maxWidth="-Infinity" minHeight="10.0" minWidth="10.0" prefHeight="400.0" prefWidth="400.0" xmlns="http://javafx.com/javafx/8.0.171" xmlns:fx="http://javafx.com/fxml/1" fx:controller="application.Controller">
<bottom>
<HBox prefHeight="50.0" prefWidth="400.0" BorderPane.alignment="CENTER">
<children>
<Button mnemonicParsing="false" onAction="#zoomIn" text="+">
<HBox.margin>
<Insets left="5.0" top="5.0" />
</HBox.margin>
</Button>
<Button mnemonicParsing="false" onAction="#zoomOut" text="-">
<HBox.margin>
<Insets left="5.0" top="5.0" />
</HBox.margin>
</Button>
<Button mnemonicParsing="false" onAction="#zoomFit" text="ZoomFit">
<HBox.margin>
<Insets left="5.0" top="5.0" />
</HBox.margin>
</Button>
<Button mnemonicParsing="false" onAction="#zoomWidth" text="ZoomWidth">
<HBox.margin>
<Insets left="5.0" top="5.0" />
</HBox.margin>
</Button>
</children>
</HBox>
</bottom>
<center>
<VBox fx:id="vbox" prefHeight="350.0" prefWidth="400.0" BorderPane.alignment="CENTER" />
</center>
</BorderPane>
Main.java
package application;
import javafx.application.Application;
import javafx.fxml.FXMLLoader;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.stage.Stage;
/**
*#author toru
*/
public class Main extends Application {
#Override
public void start(Stage primaryStage) throws Exception {
final Parent parent = FXMLLoader.load(getClass().getResource("ui.fxml"));
primaryStage.setTitle("Zoom ImageView Demo ");
primaryStage.setScene(new Scene(parent,800, 600));
primaryStage.show();
}
public static void main(String[] args) {
launch(args);
}
}
Best regards

Answer 1

Use the two-parameter renderImage(page, scale) method. 1 is the default scale and is 72 dpi, 4 is 288 dpi which is usually pretty good. So I suggest you start with scale 4, and in a later step you increase when zooming (note that rendering may become slower with higher resolutions).
So a code example for your code would be
pageImage = renderer.renderImage(pageNumber, 4);