使用PDFBox旋转图像 [英] Image rotation with PDFBox

问题描述

我不再使用PDFBox了。我需要的是将一个带旋转的图像添加到现有的PDF中！我知道如何添加图像，但我的问题是如何旋转图像！我已经看过一些关于AffineTransform和Matrix的东西，但我不知道它是什么以及它是如何工作的！

I am quit new to using PDFBox. What I need is to add an image with rotation to an exiting PDF! I know how to add the image, but my problem is how to rotate the image! I've seen somethign about AffineTransform and Matrix but I have no idea what is that and how it works!

我真的很感激传递一些示例代码，谢谢提前！

I'd really appreciate passing some sample code, and thank you in advance!

最好的问候

推荐答案

有助于了解简单图像显示方法的来源：

It helps to look at the source of the "simple" image display method:

 public void drawXObject(PDXObject xobject, float x, float y, float width, float height)
 {
     AffineTransform transform = new AffineTransform(width, 0, 0, height, x, y);
     drawXObject(xobject, transform);
 }

所以这就是你用（200,200）显示图像的方法旋转45°：

so this is what you do to display an image at (200,200) with a rotation of 45°:

 AffineTransform at = new AffineTransform(ximage.getWidth(), 0, 0, ximage.getHeight(), 200, 200);
 at.rotate(Math.toRadians(45));
 contentStream.drawXObject(ximage, at);

Re：AffineTransform：这是几何的子主题。要获得介绍，请阅读此处的Java说明。

Re: AffineTransform: this is a subtopic of geometry. To get an introduction, read the java description here.

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