处理 PDF 中的注释查看需要什么? [英] What's needed to handle annotation viewing in a PDF?

问题描述

大家好，我正在解析 PDF 内容流，以便能够读取和处理注释运算符并添加这些运算符.任何人都可以在不使用预构建库的情况下对如何进行此操作有所了解吗?我知道这是一项艰巨的任务，但我们不胜感激.

Hey everyone, I am working on parsing the PDF content stream to be able to read and handle annotation operators and also to add these. Can anyone shed some light on how to go about doing this, without using a prebuilt library? I understand it is a daunting exercise, but any pointers would be appreciated.

注意:我已经阅读了大量来自 Adob​​e 的 PDF 参考，并且主要了解文件是对象树的概念，但我不明白如何确定是否存在注释(我是否错过了参考中的这个运算符?)另外，关于回调函数本身应该负责什么的任何帮助?感谢您的帮助.

Note: I've read a fair amount of the PDF Reference from Adobe, and mostly understand the concept of the file being an object tree, yet I don't understand how to go about figuring out if an annotation is there ( did i miss this operator in the reference? ) Also, any help on what the callback functions themselves should be responsible for? Thanks for your help.

推荐答案

查看 PDF 参考 1.7 版的 3.6.2 节.每个页面树节点都有一个注释"键，其中的注释包含该页面的注释数组.每个注释都指向它在页面上的位置，而不是在内容流中包含一个页面操作符.

Look at section 3.6.2 of the PDF Reference, version 1.7. There is a "Annots" key for each Page tree node with annotations that contains an array of the annotations for that page. Each annotation points to its location on the page rather than having a page operator in the content stream.

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