将图表保存为 pdf 时消除模糊图表

Question

所以我在网上找到了一个如何将 javafx 图表保存为 pdf 的示例，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"));

现在我正在努力解决的问题是，当我将 javafx 区域图表保存到 pdf 时，图表看起来有点模糊。

例如：

如果我将 100% 缩放到 pdf，则图表“消失”： 如果我缩小到 75% 或放大到 125%，图表看起来很模糊：

现在我的问题是，是否有某种方法可以使 pdf 中的图表看起来更清晰，因为在程序中图表看起来很正常（不模糊，看起来很清晰）？

Answer 1

通过在 JavaFX 中应用缩放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

稍后创建 PDF 反向比例以使其看起来更小：

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