如何使用iText5在PDF中的多个页面上显示大尺寸的图像？ [英] How to show an image with large dimensions across multiple pages in a PDF using iText5?

问题描述

我有一个大尺寸的图形图像，我需要在PDF文件中显示。

I have a graph image with large dimensions which I need to display in a PDF file.

我无法缩放以适应图像，因为这样会产生文本节点难以辨认。

I can't scale to fit the image as this would make text on the node illegible.

如何在保留原始尺寸的同时将图像分割成多个页面？

How could I split the image into multiple pages while retaining its original dimensions?

推荐答案

请查看 TiledImage 示例。它采用原始大小的图像，并将其拼贴4页： tiled_image.pdf

Please take a look at the TiledImage example. It takes an image at its original size and it tiles it over 4 pages: tiled_image.pdf

为了使这项工作，我首先询问了图像的大小：

To make this work, I first asked the image for its size:

Image image = Image.getInstance(IMAGE);
float width = image.getScaledWidth();
float height = image.getScaledHeight();

为了确保每个页面都大到页面的四分之一，我定义了这个矩形： / p>

To make sure each page is as big as one fourth of the page, I define this rectangle:

Rectangle page = new Rectangle(width / 2, height / 2);

我在创建文档时使用此矩形实例和我使用不同的坐标添加相同的图像4次：

I use this rectangle when creating the Document instance and I add the same image 4 times using different coordinates:

Document document = new Document(page);
PdfWriter writer = PdfWriter.getInstance(document, new FileOutputStream(dest));
document.open();
PdfContentByte canvas = writer.getDirectContentUnder();
canvas.addImage(image, width, 0, 0, height, 0, -height / 2);
document.newPage();
canvas.addImage(image, width, 0, 0, height, 0, 0);
document.newPage();
canvas.addImage(image, width, 0, 0, height, -width / 2, - height / 2);
document.newPage();
canvas.addImage(image, width, 0, 0, height, -width / 2, 0);
document.close();

现在我已将图像分发到不同的页面上，这正是您想要实现的目标; - ）

Now I have distributed the image over different pages, which is exactly what you are trying to achieve ;-)

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