将图表保存为 pdf 时消除模糊图表

所以我在网上找到了一个如何将javafx图表保存为pdf的例子，所以我尝试了一下：

final AreaChart<Number, Number> arechart = new AreaChart<>(new NumberAxis(0, 3, 0.5), new NumberAxis(0, 3, 0.5));
xAxis.setLabel("average quality");
yAxis.setLabel("average quantity");
sc.setTitle("Producerdata");

XYChart.Series series1 = new XYChart.Series();
series1.setName("Water 11");

producer.getProducts().forEach((pr) -> {
    if (pr.getName().equals("Water 11")) {
        series1.getData().add(new XYChart.Data(pr.getPercentQual(), pr.getAmount()));
    }
});

XYChart.Series series2 = new XYChart.Series();
series2.setName("Water E40");
producer.getProducts().forEach((pr) -> {
    if (pr.getName().equals("Water E40")) {
        series2.getData().add(new XYChart.Data(pr.getPercentQual(), pr.getAmount()));
    }
});
arechart.getData().addAll(series1, series2);
PDDocument newPDF=new PDDocument();
PDPage chartPage = new PDPage();
newPDF.addPage(chartPage);
WritableImage image = arechart.snapshot(new SnapshotParameters(), null);
BufferedImage bf= SwingFXUtils.fromFXImage(image, null);
PDImageXObject pdImageXObject = LosslessFactory.createFromImage(newPDF, bf);
PDPageContentStream contentStream = new PDPageContentStream(newPDF, chartPage);
contentStream.drawImage(pdImageXObject, 150, 500, pdImageXObject.getWidth()  , pdImageXObject.getHeight() );
contentStream.close();
newPDF.close();
newPDF.save(new File("C:\\Users\\chelsfan\\Desktop\\TestingNetbeans\\PDFS\\chart.pdf"));

现在我遇到的问题是，当我将 javafx 区域图保存到 pdf 时，图表看起来有点模糊。

For e.g:

If I zoom 100% to the pdf the diagramm "dissapears": If I zoom out to 75% percent or zoom in to 125% the diagramm looks blurry:

Now my question is, if there is some way to make the chart in the pdf looking sharper, because in the programm the chart looks normal (not blurry,looks sharp)?

通过在 JavaFX 中应用比例变换来创建更大的图像：

SnapshotParameters sp = new SnapshotParameters();
Transform transform = Transform.scale(5, 5); // increase for larger image
sp.setTransform(transform);
WritableImage image = arechart.snapshot(sp, null);
BufferedImage bf= SwingFXUtils.fromFXImage(image, null);
ImageIO.write(bf, "png", new File("JavaFXTest.png")); // remove this line in production, this is just for you to see that the image is larger but not blurry

稍后在创建 PDF 时反向缩放以使其看起来更小：

contentStream.drawImage(pdImageXObject, 150, 500, pdImageXObject.getWidth() / 5, pdImageXObject.getHeight() / 5);