使用PDFBox在PDF上绘制矢量图像 [英] Drawing vector images on PDF with PDFBox

问题描述

我想用Apache PDFBox在PDF上绘制矢量图像.

I would like to draw a vector image on a PDF with Apache PDFBox.

这是我用来绘制常规图像的代码

This is the code I use to draw regular images

PDPage page = (PDPage) document.getDocumentCatalog().getAllPages().get(1);
PDPageContentStream contentStream = new PDPageContentStream(document, page, true, true);

BufferedImage _prevImage = ImageIO.read(new FileInputStream("path/to/image.png"));
PDPixelMap prevImage = new PDPixelMap(document, _prevImage);
contentStream.drawXObject(prevImage, prevX, prevY, imageWidth, imageHeight);

如果我使用svg或wmf图像而不是png，则生成的PDF文档将损坏.

If I use a svg or wmf image instead of png, the resulting PDF document comes corrupted.

我希望该图像为矢量图像的主要原因是，使用PNG或JPG时，该图像看起来很糟糕，我认为它已经以某种方式被压缩，因此看起来很糟糕.对于矢量图像，这种情况不应该发生(嗯，当我在Inkscape中将svg路径导出为PDF时，这种情况不会发生，矢量路径会保留下来.)

The main reason I want the image to be a vector image is that with PNG or JPG the image looks horrible, I think it gets somehow compressed so it looks bad. With vector images this shouldn't happen (well, when I export svg paths as PDF in Inkscape it doesn't happen, vector paths are preserved).

是否可以使用Apache PDFBox将svg或wmf(或其他矢量)绘制为PDF?

Is there a way to draw a svg or wmf (or other vector) to PDF using Apache PDFBox?

如果这很重要，我目前正在使用PDFBox 1.8.

I'm currently using PDFBox 1.8, if that matters.

推荐答案

请参见库 pdfbox-graphics2d ，此Jira 中被吹捧.

您可以通过蜡染或

You can draw the SVG, via Batik or Salamander or whatever, onto the class PdfBoxGraphics2D, which is parallel to iText's template.createGraphics(). See the GitHub page for samples.

PDDocument document = ...;
PDPage page = ...; // page whereon to draw

String svgXML = "<svg>...</svg>";
double leftX = ...;
double bottomY = ...; // PDFBox coordinates are oriented bottom-up!

// I set these to the SVG size, which I calculated via Salamander.
// Maybe it doesn't matter, as long as the SVG fits on the graphic.
float graphicsWidth = ...;
float graphicsHeight = ...;

// Draw the SVG onto temporary graphics.
var graphics = new PdfBoxGraphics2D(document, graphicsWidth, graphicsHeight);
try {
    int x = 0;
    int y = 0;
    drawSVG(svg, graphics, x, y); // with Batik, Salamander, or whatever you like
} finally {
    graphics.dispose();
}

// Graphics are not visible till a PDFormXObject is added.
var xform = graphics.getXFormObject();

try (var contentWriter = new PDPageContentStream(document, page, AppendMode.APPEND, false)) { // false = don't compress
    // XForm objects have to be placed via transform,
    // since they cannot be placed via coordinates like images.
    var transform = AffineTransform.getTranslateInstance(leftX, bottomY);
    xform.setMatrix(transform);

    // Now the graphics become visible.
    contentWriter.drawForm(xform);
}

还有...如果您还想将SVG图形缩放到25％大小:

And ... in case you want also to scale the SVG graphics to 25% size:

// Way 1: Scale the SVG beforehand
svgXML = String.format("<svg transform=\"scale(%f)\">%s</svg>", .25, svgXML);

// Way 2: Scale in the transform (before calling xform.setMatrix())
transform.concatenate(AffineTransform.getScaleInstance(.25, .25));

这篇关于使用PDFBox在PDF上绘制矢量图像的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！